HCS360/SN - Microchip Technology - Datasheet.Directory

HCS360

FEATURES

Security

• Programmable 28/32-bit serial number

• Programmable 64-bit encryption key

• Each transmission is unique

• 67-bit transmission code length

• 32-bit hopping code

• 35-bit fixed code (28/32-bit serial number,

4/0-bit function code, 1-bit status, 2-bit CRC)

• Encryption keys are read protected

Operating

• 2.0-6.6V operation

• Four button inputs

- 15 functions available

• Selectable baud rate

• Automatic code word completion

• Battery low signal transmitted to receiver

• Nonvolatile synchronization data

• PWM and Manchester modulation

Other

• Easy-to-use programming interface

• On-chip EEPROM

• On-chip oscillator and timing components

• Button inputs have internal pull-down resistors

• Current limiting on LED output

• Minimum component count

Enhanced Features Over HCS300

• 48-bit seed vs. 32-bit seed

• 2-bit CRC for error detection

• 28/32-bit serial number select

• Two seed transmission methods

• PWM and Manchester modulation

• IR Modulation mode

Typical Applications

The HCS360 is ideal for Remote Keyless Entry (RKE)

applications. These applications include:

• Automotive RKE systems

• Automotive alarm systems

• Automotive immobilizers

• Gate and garage door openers

• Identity tokens

• Burglar alarm systems

DESCRIPTION

The HCS360 is a code hopping encoder designed for

secure Remote Keyless Entry (RKE) systems. The

HCS360 utilizes the KEELOQ® code hopping technol-

ogy, which incorporates high security, a small package

outline and low cost, to make this device a perfect

solution for unidirectional remote keyless entry sys-

tems and access control systems.

PACKAGE TYPES

BLOCK DIAGRAM

The HCS360 combines a 32-bit hopping code

generated by a nonlinear encryption algorithm, with a

28/32-bit serial number and 7/3 status bits to create a

67-bit transmission stream.

VDD

LED

DATA

VSS

PDIP, SOIC

HCS360

VSS

VDD

Oscillator

RESET circuit

LED driver

Controller

Power

latching

and

switching

Button input port

32-bit shift register

Encoder

EEPROM

DATA

LED

S3S2S1S0

KEELOQ® Code Hopping Encoder

HCS360

The crypt key, serial number and configuration data are

stored in an EEPROM array which is not accessible via

any external connection. The EEPROM data is pro-

grammable but read-protected. The data can be veri-

fied only after an automatic erase and programming

operation. This protects against attempts to gain

access to keys or manipulate synchronization values.

The HCS360 provides an easy-to-use serial interface

for programming the necessary keys, system parame-

ters and configuration data.

1.0 SYSTEM OVERVIEW

Key Terms

The following is a list of key terms used throughout this

data sheet. For additional information on KEELOQ and

Code Hopping, refer to Technical Brief 3 (TB003).

•RKE - Remote Keyless Entry

•Button Status - Indicates what button input(s)

activated the transmission. Encompasses the 4

button status bits S3, S2, S1 and S0 (Figure 3-1).

•Code Hopping - A method by which a code,

viewed externally to the system, appears to

change unpredictably each time it is transmitted.

•Code word - A block of data that is repeatedly

transmitted upon button activation (Figure 3-1).

•Transmission - A data stream consisting of

repeating code words (Figure 9-1).

•Crypt key - A unique and secret 64-bit number

used to encrypt and decrypt data. In a symmetri-

cal block cipher such as the KEELOQ algorithm,

the encryption and decryption keys are equal and

will therefore be referred to generally as the crypt

key.

•Encoder - A device that generates and encodes

data.

•Encryption Algorithm - A recipe whereby data is

scrambled using a crypt key. The data can only be

interpreted by the respective decryption algorithm

using the same crypt key.

•Decoder - A device that decodes data received

from an encoder.

•Decryption algorithm - A recipe whereby data

scrambled by an encryption algorithm can be

unscrambled using the same crypt key.

•Learn – Learning involves the receiver calculating

the transmitter’s appropriate crypt key, decrypting

the received hopping code and storing the serial

number, synchronization counter value and crypt

key in EEPROM. The KEELOQ product family facil-

itates several learning strategies to be imple-

mented on the decoder. The following are

examples of what can be done.

-Simple Learning

The receiver uses a fixed crypt key, common

to all components of all systems by the same

manufacturer, to decrypt the received code

word’s encrypted portion.

-Normal Learning

The receiver uses information transmitted

during normal operation to derive the crypt

key and decrypt the received code word’s

encrypted portion.

-Secure Learn

The transmitter is activated through a special

button combination to transmit a stored 60-bit

seed value used to generate the transmitter’s

crypt key. The receiver uses this seed value

to derive the same crypt key and decrypt the

received code word’s encrypted portion.

•Manufacturer’s code – A unique and secret 64-

bit number used to generate unique encoder crypt

keys. Each encoder is programmed with a crypt

key that is a function of the manufacturer’s code.

Each decoder is programmed with the manufac-

turer code itself.

The HCS360 code hopping encoder is designed specif-

ically for keyless entry systems; primarily vehicles and

home garage door openers. The encoder portion of a

keyless entry system is integrated into a transmitter,

carried by the user and operated to gain access to a

vehicle or restricted area. The HCS360 is meant to be

a cost-effective yet secure solution to such systems,

requiring very few external components (Figure 2-1).

Most low-end keyless entry transmitters are given a

fixed identification code that is transmitted every time a

button is pushed. The number of unique identification

codes in a low-end system is usually a relatively small

number. These shortcomings provide an opportunity

for a sophisticated thief to create a device that ‘grabs’

a transmission and retransmits it later, or a device that

quickly ‘scans’ all possible identification codes until the

correct one is found.

The HCS360, on the other hand, employs the KEELOQ

code hopping technology coupled with a transmission

length of 66 bits to virtually eliminate the use of code

‘grabbing’ or code ‘scanning’. The high security level of

the HCS360 is based on the patented KEELOQ technol-

ogy. A block cipher based on a block length of 32 bits

and a key length of 64 bits is used. The algorithm

obscures the information in such a way that even if the

transmission information (before coding) differs by only

one bit from that of the previous transmission, the next

HCS360

coded transmission will be completely different. Statis-

tically, if only one bit in the 32-bit string of information

changes, greater than 50 percent of the coded trans-

mission bits will change.

As indicated in the block diagram on page one, the

HCS360 has a small EEPROM array which must be

loaded with several parameters before use; most often

programmed by the manufacturer at the time of produc-

tion. The most important of these are:

• A 28-bit serial number, typically unique for every

encoder

• A crypt key

• An initial 16-bit synchronization value

• A 16-bit configuration value

The crypt key generation typically inputs the transmitter

serial number and 64-bit manufacturer’s code into the

key generation algorithm (Figure 1-1). The manufac-

turer’s code is chosen by the system manufacturer and

must be carefully controlled as it is a pivotal part of the

overall system security.

FIGURE 1-1: CREATION AND STORAGE OF CRYPT KEY DURING PRODUCTION

The 16-bit synchronization counter is the basis behind

the transmitted code word changing for each transmis-

sion; it increments each time a button is pressed. Due

to the code hopping algorithm’s complexity, each incre-

ment of the synchronization value results in greater

than 50% of the bits changing in the transmitted code

word.

Figure 1-2 shows how the key values in EEPROM are

used in the encoder. Once the encoder detects a button

press, it reads the button inputs and updates the syn-

chronization counter. The synchronization counter and

crypt key are input to the encryption algorithm and the

output is 32 bits of encrypted information. This data will

change with every button press, its value appearing

externally to ‘randomly hop around’, hence it is referred

to as the hopping portion of the code word. The 32-bit

hopping code is combined with the button information

and serial number to form the code word transmitted to

the receiver. The code word format is explained in

greater detail in Section 4.2.

A receiver may use any type of controller as a decoder,

but it is typically a microcontroller with compatible firm-

ware that allows the decoder to operate in conjunction

with an HCS360 based transmitter. Section 7.0

provides detail on integrating the HCS360 into a sys-

tem.

A transmitter must first be ‘learned’ by the receiver

before its use is allowed in the system. Learning

includes calculating the transmitter’s appropriate crypt

key, decrypting the received hopping code and storing

the serial number, synchronization counter value and

crypt key in EEPROM.

In normal operation, each received message of valid

format is evaluated. The serial number is used to deter-

mine if it is from a learned transmitter. If from a learned

transmitter, the message is decrypted and the synchro-

nization counter is verified. Finally, the button status is

checked to see what operation is requested. Figure 1-3

shows the relationship between some of the values

stored by the receiver and the values received from

the transmitter.

Transmitter

Manufacturer’s

Serial Number

Code

Crypt

Key

Generation

Algorithm

Serial Number

Crypt Key

Sync Counter

HCS360

Production

Programmer EEPROM Array

HCS360

FIGURE 1-2: BUILDING THE TRANSMITTED CODE WORD (ENCODER)

FIGURE 1-3: BASIC OPERATION OF RECEIVER (DECODER)

NOTE: Circled numbers indicate the order of execution.

Button Press

Information

EEPROM Array

32 Bits

Encrypted Data

Serial Number

Transmitted Information

Crypt Key

Sync Counter

Serial Number

KEELOQ®

Encryption

Algorithm

Button Press

Information

EEPROM Array

Manufacturer Code

32 Bits of

Encrypted Data

Serial Number

Received Information

Decrypted

Synchronization

Counter

Check for

Match

Sync Counter

Serial Number

KEELOQ®

Decryption

Algorithm

Check for

Match

Perform Function

Indicated by

button press

Crypt Key

HCS360

2.0 DEVICE OPERATION

As shown in the typical application circuits (Figure 2-1),

the HCS360 is a simple device to use. It requires only

the addition of buttons and RF circuitry for use as the

transmitter in your security application. A description of

each pin is described in Table 2-1.

FIGURE 2-1: TYPICAL CIRCUITS

TABLE 2-1: PIN DESCRIPTIONS

The HCS360 will wake-up upon detecting a button

press and delay approximately 10 ms for button

debounce (Figure 2-2). The synchronization counter,

discrimination value and button information will be

encrypted to form the hopping code. The hopping code

portion will change every transmission, even if the

same button is pushed again. A code word that has

been transmitted will not repeat for more than 64K

transmissions. This provides more than 18 years of use

before a code is repeated; based on 10 operations per

day. Overflow information sent from the encoder can be

used to extend the number of unique transmissions to

more than 192K.

If in the transmit process it is detected that a new but-

ton(s) has been pressed, a RESET will immediately

occur and the current code word will not be completed.

Please note that buttons removed will not have any

effect on the code word unless no buttons remain

pressed; in which case the code word will be completed

and the power-down will occur.

FIGURE 2-2: ENCODER OPERATION

Name Pin

Number Description

S0 1 Switch input 0

S1 2 Switch input 1

S2 3 Switch input 2 / Clock pin when in

Programming mode

S3 4 Switch input 3

VSS 5Ground reference

DATA 6 Data output pin /Data I/O pin for

Programming mode

LED 7Cathode connection for LED

VDD 8Positive supply voltage

VDD

Tx out

LED

VDD

DATA

VSS

Two button remote control

VDD

Tx out

LED

VDD

DATA

VSS

Five button remote control (Note1)

B4 B3 B2 B1 B0

Note: Up to 15 functions can be implemented by pressing

more than one button simultaneously or by using a

suitable diode array.

Power-Up

RESET and Debounce Delay

(10 ms)

Sample Inputs

Update Sync Info

Encrypt With

Load Transmit Register

Buttons

Added

All

Buttons

Released

(A button has been pressed)

Transmit

Stop

Yes

Crypt Key

Complete Code

Word Transmission

HCS360

3.0 EEPROM MEMORY

ORGANIZATION

The HCS360 contains 192 bits (12 x 16-bit words) of

EEPROM memory (Table 3-1). This EEPROM array is

used to store the crypt key information, synchronization

value, etc. Further descriptions of the memory array is

given in the following sections.

TABLE 3-1: EEPROM MEMORY MAP

3.1 KEY_0 - KEY_3 (64-Bit Crypt Key)

The 64-bit crypt key is used to create the encrypted

message transmitted to the receiver. This key is calcu-

lated and programmed during production using a key

generation algorithm. The key generation algorithm

may be different from the KEELOQ algorithm. Inputs to

the key generation algorithm are typically the transmit-

ter’s serial number and the 64-bit manufacturer’s code.

While the key generation algorithm supplied from

Microchip is the typical method used, a user may elect

to create their own method of key generation. This may

be done providing that the decoder is programmed with

the same means of creating the key for

decryption purposes.

3.2 SYNC_A, SYNC_B

(Synchronization Counter)

This is the 16-bit synchronization value that is used to

create the hopping code for transmission. This value is

incremented after every transmission. Separate syn-

chronization counters can be used to stay synchro-

nized with different receivers.

3.3 SEED_0, SEED_1, and SEED_2

(Seed Word)

The three word (48 bits) seed code will be transmitted

when seed transmission is selected. This allows the sys-

tem designer to implement the Secure Learn feature or

use this fixed code word as part of a different key genera-

tion/tracking process or purely as a fixed code transmis-

sion.

3.4 SER_0, SER_1

(Encoder Serial Number)

SER_0 and SER_1 are the lower and upper words of

the device serial number, respectively. There are 32

bits allocated for the Serial Number and a selectable

configuration bit determines whether 32 or 28 bits will

be transmitted. The serial number is meant to be

unique for every transmitter.

WORD

ADDRESS MNEMONIC DESCRIPTION

0 KEY_0 64-bit crypt key

(word 0) LSb’s

1 KEY_1 64-bit crypt key

(word 1)

2 KEY_2 64-bit crypt key

(word 2)

3 KEY_3 64-bit crypt key

(word 3) MSb’s

4 SYNC_A 16-bit synch counter

5 SYNC_B/

SEED_2

16-bit synch counter B

or Seed value (word 2)

6 RESERVED Set to 0000H

7 SEED_0 Seed Value

(word 0) LSb’s

8 SEED_1 Seed Value

(word 1) MSb’s

9 SER_0 Device Serial Number

(word 0) LSb’s

10 SER_1 Device Serial Number

(word 1) MSb’s

11 CONFIG Configuration Word

Note: Since SEED2 and SYNC_B share the

same memory location, Secure Learn and

Independent mode transmission (including

IR mode) are mutually exclusive.

HCS360

3.5 CONFIG

(Configuration Word)

The Configuration Word is a 16-bit word stored in

EEPROM array that is used by the device to store

information used during the encryption process, as well

as the status of option configurations. Further

explanations of each of the bits are described in the

following sections.

TABLE 3-2: CONFIGURATION WORD.

3.5.1 MOD: MODULATION FORMAT

MOD selects between Manchester code modulation

and PWM modulation.

If MOD = 1, Manchester modulation is selected:

If MOD = 0, PWM modulation is selected.

3.5.2 BSEL 1, 0

BAUD RATE SELECTION

BSEL 1 and BSEL 0 determine the baud rate according

to Table 3-3 when PWM modulation is selected.

TABLE 3-3: BAUD RATE SELECTION

BSEL 1 and BSEL 0 determine the baud rate according

to Table 3-4 when Manchester modulation is selected.

TABLE 3-4: BAUD RATE SELECTION

3.5.3 OVR: OVERFLOW

The overflow bit is used to extend the number of possi-

ble synchronization values. The synchronization coun-

ter is 16 bits in length, yielding 65,536 values before the

cycle repeats. Under typical use of 10 operations a day,

this will provide nearly 18 years of use before a

repeated value will be used. Should the system

designer conclude that is not adequate, then the over-

flow bit can be utilized to extend the number of unique

values. This can be done by programming OVR to 1 at

the time of production. The encoder will automatically

clear OVR the first time that the transmitted synchroni-

zation value wraps from 0xFFFF to 0x0000. Once

cleared, OVR cannot be set again, thereby creating a

permanent record of the counter overflow. This pre-

vents fast cycling of 64K counter. If the decoder system

is programmed to track the overflow bits, then the effec-

tive number of unique synchronization values can be

extended to 128K. If programmed to zero, the system

will be compatible with old encoder devices.

3.5.4 LNGRD: LONG GUARD TIME

LNGRD = 1 selects the encoder to extend the guard

time between code words adding ≈50 ms. This can be

used to reduce the average power transmitted over a

100 ms window and thereby transmit a higher peak

power.

Bit Number Symbol Bit Description

0 LNGRD Long Guard Time

1 BSEL 0 Baud Rate Selection

2 BSEL 1 Baud Rate Selection

3NUNot Used

4 SEED Seed Transmission enable

5 DELM Delay mode enable

6 TIMO Time-out enable

7 IND Independent mode enable

8 USRA0 User bit

9 USRA1 User bit

10 USRB0 User bit

11 USRB1 User bit

12 XSER Extended serial number

enable

13 TMPSD Temporary seed transmis-

sion enable

14 MOD Manchester/PWM modula-

tion selection

15 OVR Overflow bit

MOD BSEL 1 BSEL 0 TEUnit

0 0 0 400 us

0 0 1 200 us

0 1 0 200 us

0 1 1 100 us

MOD BSEL 1 BSEL 0 TEUnit

1 0 0 800 us

1 0 1 400 us

1 1 0 400 us

1 1 1 200 us

HCS360

3.5.5 XSER: EXTENDED SERIAL

NUMBER

If XSER = 0, the four Most Significant bits of the Serial

Number are substituted by S[3:0] and the code word

format is compatible with the HCS200/300/301.

If XSER = 1, the full 32-bit Serial Number [SER_1,

SER_0] is transmitted.

3.5.6 DISCRIMINATION VALUE

While in other KEELOQ encoders its value is user

selectable, the HCS360 uses directly the 8 Least Sig-

nificant bits of the Serial Number as part of the infor-

mation that form the encrypted portion of the

transmission (Figure 3-1).

The discrimination value aids the post-decryption

check on the decoder end. After the receiver has

decrypted a transmission, the discrimination bits are

checked against the encoder Serial Number to verify

that the decryption process was valid.

3.5.7 USRA,B: USER BITS

User bits form part of the discrimination value. The user

bits together with the IND bit can be used to identify the

counter that is used in Independent mode.

FIGURE 3-1: CODE WORD ORGANIZATION

Note: Since the button status S[3:0] is used to

detect a Seed transmission, Extended

Serial Number and Secure Learn are

mutually exclusive.

Discrimination Bits

(12 bits)

IOUUSS...S

NV S S E E ...E

DR R RR R ...R

1076...0

Fixed Code Portion of Transmission Encrypted Portion of Transmission

67 bits

of Data

Transmitted

MSB LSB

CRC

(2-bit) VLOW

(1-bit)

Button

Status

(4 bits)

28-bit

Serial Number

Button

Status

(4 bits)

Discrimination

bits

(12 bits)

16-bit

Sync Value

Button Status

(4 bits)

SS S S

21 0 3

Fixed Code Portion of Transmission Encrypted Portion of Transmission

MSB LSB

CRC

(2-bit) VLOW

(1-bit) 32-bit

Extended Serial Number

Button

Status

(4 bits)

Discrimination

bits

(12 bits)

16-bit

Sync Value

XSER=1

XSER=0

HCS360

3.5.8 SEED: ENABLE SEED

TRANSMISSION

If SEED = 0, seed transmission is disabled. The Inde-

pendent Counter mode can only be used with seed

transmission disabled since SEED_2 is shared with the

second synchronization counter.

With SEED = 1, seed transmission is enabled. The

appropriate button code(s) must be activated to trans-

mit the seed information. In this mode, the seed infor-

mation (SEED_0, SEED_1, and SEED_2) and the

upper 12 or 16 bits of the serial number (SER_1) are

transmitted instead of the hop code.

Seed transmission is available for function codes

(Table 3-9) S[3:0] = 1001 and S[3:0] = 0011(delayed).

This takes place regardless of the setting of the IND bit.

The two seed transmissions are shown in Figure 3-2.

FIGURE 3-2: Seed Transmission

3.5.9 TMPSD: TEMPORARY SEED

TRANSMISSION

The temporary seed transmission can be used to dis-

able learning after the transmitter has been used for a

programmable number of operations. This feature can

be used to implement very secure systems. After learn-

ing is disabled, the seed information cannot be

accessed even if physical access to the transmitter is

possible. If TMPSD = 1 the seed transmission will be

disabled after a number of code hopping transmis-

sions. The number of transmissions before seed trans-

mission is disabled, can be programmed by setting the

synchronization counter (SYNC_A, SYNC_B) to a

value as shown in Table 3-5.

TABLE 3-5: SYNCHRONOUS COUNTER

INITIALIZATION VALUES

All examples shown with XSER = 1, SEED = 1

When S[3:0] = 1001, delay is not acceptable.

CRC+VLOW SER_1 SEED_2 SEED_1 SEED_0

Data transmission direction

For S[3:0] = 0x3 before delay:

16-bit Data Word 16-bit Counter

Encrypt

CRC+VLOW SER_1 SER_0 Encrypted Data

For S[3:0] = 0011 after delay (Note 1, Note 2):

CRC+VLOW SER_1 SEED_2 SEED_1 SEED_0

Data transmission direction

Note 1: For Seed Transmission, SEED_2 is transmitted instead of SER_0.

2: For Seed Transmission, the setting of DELM has no effect.

Synchronous Counter

Values

Number of

Transmissions

0000H 128

0060H 64

0050H 32

0048H 16

HCS360

3.5.10 DELM: DELAY MODE

If DELM = 1, delay transmission is enabled. A delayed

transmission is indicated by inverting the lower nibble

of the discrimination value. The Delay mode is primarily

for compatibility with previous KEELOQ devices and is

not recommended for new designs.

If DELM = 0, delay transmission is disabled (Table 3-

6).

TABLE 3-6: TYPICAL DELAY TIMES

3.5.11 TIMO: TIME-OUT

OR AUTO-SHUTOFF

If TIMO = 1, the time-out is enabled. Time-out can be

used to terminate accidental continuous transmissions.

When time-out occurs, the PWM output is set low and

the LED is turned off. Current consumption will be

higher than in Standby mode since current will flow

through the activated input resistors. This state can be

exited only after all inputs are taken low. TIMO = 0, will

enable continuous transmission (Table 3-7).

TABLE 3-7: TYPICAL TIME-OUT TIMES

BSEL 1 BSEL 0

Number of Code

Words before Delay

Mode

Time Before Delay Mode

(MOD = 0)

Time Before Delay Mode

(MOD = 1)

00 28 ≈ 2.9s ≈ 5.1s

01 56 ≈ 3.1s ≈ 6.4s

10 28 ≈ 1.5s ≈ 3.2s

11 56 ≈ 1.7s ≈ 4.5s

BSEL 1 BSEL 0

Maximum Number of

Code Words

Transmitted

Time Before Time-out

(MOD = 0)

Time Before Time-out

(MOD = 1)

0 0 256 ≈ 26.5s ≈ 46.9

0 1 512 ≈ 28.2s ≈ 58.4

1 0 256 ≈ 14.1s ≈ 29.2

1 1 512 ≈ 15.7s ≈ 40.7

HCS360

3.5.12 IND: INDEPENDENT MODE

The Independent mode can be used where one

encoder is used to control two receivers. Two counters

(SYNC_A and SYNC_B) are used in Independent

mode. As indicated in Table 3-9, function codes 1 to 7

use SYNC_A and 8 to 15 SYNC_B.

3.5.13 INFRARED MODE

The Independent mode also selects IR mode. In IR

mode function codes 12 to 15 will use SYNC_B. The

PWM output signal is modulated with a 40 kHz carrier

(see Table 3-8). It must be pointed out that the 40 kHz

is derived from the internal clock and will therefore vary

with the same percentage as the baud rate. If IND = 0,

SYNC_A is used for all function codes. If IND = 1, Inde-

pendent mode is enabled and counters for functions

are used according to Table 3-9.

TABLE 3-8: IR MODULATION

TABLE 3-9: FUNCTION CODES

Note 1: IR mode

TEBasic Pulse

800us

400us

200us

100us

(800μs)

(32x)

(400μs)

(16x)

(200μs)

(8x)

Period = 25μs

(100μs)

(4x)

S3 S2 S1 S0 IND = 0 IND = 1 Comments

Counter

10001 A A

20010 A A

30011 A AIf SEED = 1, transmit seed after delay.

40100 A A

50101 A A

60110 A A

70111 A A

81000 A B

91001 A BIf SEED = 1, transmit seed immediately.

101010 A B

111011 A B

121100 A B(1)

131101 A B(1)

141110 A B(1)

151111 A B(1)

HCS360

4.0 TRANSMITTED WORD

4.1 Transmission Format (PWM)

The HCS360 code word is made up of several parts

(Figure 4-1 and Figure 4-2). Each code word contains

a 50% duty cycle preamble, a header, 32 bits of

encrypted data and 35 bits of fixed data followed by a

guard period before another code word can begin.

Refer to Table 9-3 and Table 9-5 for code word timing.

4.2 Code Word Organization

The HCS360 transmits a 67-bit code word when a but-

ton is pressed. The 67-bit word is constructed from a

Fixed Code portion and an Encrypted Code portion

(Figure 3-1).

The Encrypted Data is generated from 4 function bits,

2 user bits, overflow bit, Independent mode bit, and 8

serial number bits, and the 16-bit synchronization value

(Figure 3-1). The encrypted portion alone provides up

to four billion changing code combinations.

The Fixed Code Data is made up of a VLOW bit, 2 CRC

bits, 4 function bits, and the 28-bit serial number. If the

extended serial number (32 bits) is selected, the 4 func-

tion code bits will not be transmitted. The fixed and

encrypted sections combined increase the number of

code combinations to 7.38 x 1019

FIGURE 4-1: CODE WORD FORMAT (PWM)

FIGURE 4-2: CODE WORD FORMAT (MANCHESTER)

LOGIC "1"

Guard

Time

31XTEEncrypted Portion Fixed Portion

LOGIC "0"

Preamble

Header

10xTE

116

of Transmission

Preamble

50% Duty Cycle

Guard

Preamble Header

Encrypted Portion Fixed Portion

START bit STOP bit

Time

bit 0

bit 1

bit 2

LOGIC "0"

LOGIC "1"

TETE

4XTE

31XTE

of Transmission of Transmission

Preamble

50% Duty Cycle

HCS360

5.0 SPECIAL FEATURES

5.1 Code Word Completion

Code word completion is an automatic feature that

ensures that the entire code word is transmitted, even

if the button is released before the transmission is com-

plete and that a minimum of two words are completed.

The HCS360 encoder powers itself up when a button is

pushed and powers itself down after two complete

words are transmitted if the user has already released

the button. If the button is held down beyond the time

for one transmission, then multiple transmissions will

result. If another button is activated during a

transmission, the active transmission will be aborted

and the new code will be generated using the new

button information.

5.2 Long Guard Time

Federal Communications Commission (FCC) part 15

rules specify the limits on fundamental power and

harmonics that can be transmitted. Power is calculated

on the worst case average power transmitted in a 100

ms window. It is therefore advantageous to minimize

the duty cycle of the transmitted word. This can be

achieved by minimizing the duty cycle of the individual

bits or by extending the guard time between transmis-

sions. Long guard time (LNGRD) is used for reducing

the average power of a transmission. This is a select-

able feature. Using the LNGRD allows the user to

transmit a higher amplitude transmission if the

transmission time per 100 ms is shorter. The FCC puts

constraints on the average power that can be

transmitted by a device, and LNGRD effectively

prevents continuous transmission by only allowing the

transmission of every second word. This reduces the

average power transmitted and hence, assists in FCC

approval of a transmitter device.

5.3 CRC (Cycle Redundancy Check)

Bits

The CRC bits are calculated on the 65 previously trans-

mitted bits. The CRC bits can be used by the receiver

to check the data integrity before processing starts. The

CRC can detect all single bit and 66% of double bit

errors. The CRC is computed as follows:

EQUATION 5-1: CRC Calculation

and

with

and

Din the nth transmission bit 0 ≤ n ≤ 64

Note: The CRC may be wrong when the battery

voltage is around either of the VLOW trip

points. This may happen because VLOW is

sampled twice each transmission, once for

the CRC calculation (PWM is low) and once

when VLOW is transmitted (PWM is high).

VDD tends to move slightly during a transmis-

sion which could lead to a different value for

VLOW being used for the CRC calculation

and the transmission

. Work around: If the CRC calculation is incor-

rect, recalculate for the opposite value of

VLOW.

CRC 1[]

n1+CRC 0[]

nDin

∧=

CRC 0[]

n1+CRC 0[]

nDin

∧()CRC 1[]

∧=

CRC 10,[]

00=

HCS360

5.4 Auto-shutoff

The Auto-shutoff function automatically stops the

device from transmitting if a button inadvertently gets

pressed for a long period of time. This will prevent the

device from draining the battery if a button gets

pressed while the transmitter is in a pocket or purse.

This function can be enabled or disabled and is

selected by setting or clearing the time-out bit

(Section 3.5.11). Setting this bit will enable the function

(turn Auto-shutoff function on) and clearing the bit will

disable the function. Time-out period is approximately

25 seconds.

5.5 VLOW: Voltage LOW Indicator

The VLOW bit is transmitted with every transmission

(Figure 3-1) and will be transmitted as a one if the

operating voltage has dropped below the low voltage

trip point, typically 3.8V at 25°C. This VLOW signal is

transmitted so the receiver can give an indication to the

user that the transmitter battery is low.

5.6 LED Output Operation

During normal transmission the LED output is LOW

while the data is being transmitted and high during the

guard time. Two voltage indications are combined into

one bit: VLOW. Table 5-1 indicates the operation value

of VLOW while data is being transmitted.

FIGURE 5-1: VLOW Trip Point VS.

Temperature

If the supply voltage drops below the low voltage trip

point, the LED output will be toggled at approximately

1Hz during the transmission.

TABLE 5-1: VLOW AND LED VS. VDD

*See also FLASH operating modes.

Approximate

Supply Voltage

VLOW Bit LED Operation*

Max → 3.8V 0 Normal

3.8V → 2.2V 1 Flashing

2.2V → Min 0 Normal

3.5

-40 25 85

VLOW=0

Nominal Trip Point

3.8V

VLOW=1

VLOW=0 Nominal Trip

Point

4.5

3.5

2.5

1.5

HCS360

6.0 PROGRAMMING THE HCS360

When using the HCS360 in a system, the user will have

to program some parameters into the device including

the serial number and the secret key before it can be

used. The programming allows the user to input all 192

bits in a serial data stream, which are then stored inter-

nally in EEPROM. Programming will be initiated by

forcing the PWM line high, after the S3 line has been

held high for the appropriate length of time. S0 should

be held low during the entire program cycle. The S1

line on the HCS360 part needs to be set or cleared

depending on the LS bit of the memory map (Key 0)

before the key is clocked in to the HCS360. S1 must

remain at this level for the duration of the programming

cycle. The device can then be programmed by clocking

in 16 bits at a time, followed by the word’s complement

using S3 or S2 as the clock line and PWM as the data

in line. After each 16-bit word is loaded, a programming

delay is required for the internal program cycle to com-

plete. The Acknowledge can read back after the pro-

gramming delay (TWC). After the first word and its

complement have been downloaded, an automatic

bulk write is performed. This delay can take up to Twc.

At the end of the programming cycle, the device can be

verified (Figure 6-1) by reading back the EEPROM.

Reading is done by clocking the S3 line and reading the

data bits on PWM. For security reasons, it is not possi-

ble to execute a Verify function without first program-

ming the EEPROM. A Verify operation can only be

done once, immediately following the Program

cycle.

FIGURE 6-1: Programming Waveforms

FIGURE 6-2: Verify Waveforms

The VDD pin must be taken to ground after a program/verify cycle.

DATA

Enter Program

Mode

(Data)

(Clock)

Bit 1 Bit 2 Bit 3 Bit 14 Bit 15 Bit 16 Bit 17

Repeat for each word

TCLKH

TCLKL

TWC

TDS

S2/S3

Data for Word 0 (KEY_0) Data for Word 1

TDH

Bit 0 Bit 1 Bit 2 Bit 3 Bit 14 Bit 15

Bit 0

Bit 0 of Word0

Note 1: Unused button inputs to be held to ground during the entire programming sequence.

2: The VDD pin must be taken to ground after a Program/Verify cycle.

Acknowledge Pulse

DATA

(Clock)

(Data)

Note: A Verify sequence is performed only once immediately after the Program cycle.

End of Programming Cycle Beginning of Verify Cycle

Bit 1 Bit 2 Bit 3 Bit 15Bit 14 Bit 16 Bit 17 Bit190 Bit191

TWC

Data from Word0

TDV

S2/S3

Bit 0Bit191Bit190

Ack

HCS360

TABLE 6-3: PROGRAMMING/VERIFY TIMING REQUIREMENTS

Note 1: Typical values - not tested in production.

VDD = 5.0V ± 10%

25° C ± 5 °C

Parameter Symbol Min. Max. Units

Program mode setup time T204.0ms

Hold time 1 T19.0 — ms

Program cycle time TWC 50 — ms

Clock low time TCLKL 50 — μs

Clock high time TCLKH 50 — μs

Data setup time TDS 0—

μs(1)

Data hold time TDH 30 — μs(1)

Data out valid time TDV —30

μs(1)

HCS360

7.0 INTEGRATING THE HCS360

INTO A SYSTEM

Use of the HCS360 in a system requires a compatible

decoder. This decoder is typically a microcontroller with

compatible firmware. Microchip will provide (via a

license agreement) firmware routines that accept

transmissions from the HCS360 and decrypt the

hopping code portion of the data stream. These

routines provide system designers the means to

develop their own decoding system.

7.1 Learning a Transmitter to a

Receiver

A transmitter must first be 'learned' by a decoder before

its use is allowed in the system. Several learning strat-

egies are possible, Figure 7-1 details a typical learn

sequence. Core to each, the decoder must minimally

store each learned transmitter's serial number and cur-

rent synchronization counter value in EEPROM. Addi-

tionally, the decoder typically stores each transmitter's

unique crypt key. The maximum number of learned

transmitters will therefore be relative to the available

EEPROM.

A transmitter's serial number is transmitted in the clear

but the synchronization counter only exists in the code

word's encrypted portion. The decoder obtains the

counter value by decrypting using the same key used

to encrypt the information. The KEELOQ algorithm is a

symmetrical block cipher so the encryption and decryp-

tion keys are identical and referred to generally as the

crypt key. The encoder receives its crypt key during

manufacturing. The decoder is programmed with the

ability to generate a crypt key as well as all but one

required input to the key generation routine; typically

the transmitter's serial number.

Figure 7-1 summarizes a typical learn sequence. The

decoder receives and authenticates a first transmis-

sion; first button press. Authentication involves gener-

ating the appropriate crypt key, decrypting, validating

the correct key usage via the discrimination bits and

buffering the counter value. A second transmission is

received and authenticated. A final check verifies the

counter values were sequential; consecutive button

presses. If the learn sequence is successfully com-

plete, the decoder stores the learned transmitter's

serial number, current synchronization counter value

and appropriate crypt key. From now on the crypt key

will be retrieved from EEPROM during normal opera-

tion instead of recalculating it for each transmission

received.

Certain learning strategies have been patented and

care must be taken not to infringe.

FIGURE 7-1: TYPICAL LEARN

SEQUENCE

Enter Learn

Mode

Wait for Reception

of a Valid Code

Generate Key

from Serial Number

Use Generated Key

to Decrypt

Compare Discrimination

Value with Fixed Value

Equal

Wait for Reception

of Second Valid Code

Compare Discrimination

Value with Fixed Value

Use Generated Key

to Decrypt

Equal

Counters

Encryption key

Serial number

Synchronization counter

Sequential

Exit

Learn successful Store: Learn

Unsuccessful

Yes

HCS360

7.2 Decoder Operation

Figure 7-2 summarizes normal decoder operation. The

decoder waits until a transmission is received. The

received serial number is compared to the EEPROM

table of learned transmitters to first determine if this

transmitter's use is allowed in the system. If from a

learned transmitter, the transmission is decrypted

using the stored crypt key and authenticated via the

discrimination bits for appropriate crypt key usage. If

the decryption was valid the synchronization value is

evaluated.

FIGURE 7-2: TYPICAL DECODER

OPERATION

7.3 Synchronization with Decoder

(Evaluating the Counter)

The KEELOQ technology patent scope includes a

sophisticated synchronization technique that does not

require the calculation and storage of future codes. The

technique securely blocks invalid transmissions while

providing transparent resynchronization to transmitters

inadvertently activated away from the receiver.

Figure 7-3 shows a 3-partition, rotating synchronization

window. The size of each window is optional but the

technique is fundamental. Each time a transmission is

authenticated, the intended function is executed and

the transmission's synchronization counter value is

stored in EEPROM. From the currently stored counter

value there is an initial "Single Operation" forward win-

dow of 16 codes. If the difference between a received

synchronization counter and the last stored counter is

within 16, the intended function will be executed on the

single button press and the new synchronization coun-

ter will be stored. Storing the new synchronization

counter value effectively rotates the entire synchroniza-

tion window.

A "Double Operation" (resynchronization) window fur-

ther exists from the Single Operation window up to 32K

codes forward of the currently stored counter value. It

is referred to as "Double Operation" because a trans-

mission with synchronization counter value in this win-

dow will require an additional, sequential counter

transmission prior to executing the intended function.

Upon receiving the sequential transmission the

decoder executes the intended function and stores the

synchronization counter value. This resynchronization

occurs transparently to the user as it is human nature

to press the button a second time if the first was unsuc-

cessful.

The third window is a "Blocked Window" ranging from

the double operation window to the currently stored

synchronization counter value. Any transmission with

synchronization counter value within this window will

be ignored. This window excludes previously used,

perhaps code-grabbed transmissions from accessing

the system.

Transmission

Received

Does

Serial Number

Match

Decrypt Transmission

Decryption

Valid

Counter

Within 16

Counter

Within 32K

Update

Counter

Execute

Command

Save Counter

in Temp Location

Start

Yes

and

Note: The synchronization method described in

this section is only a typical implementation

and because it is usually implemented in

firmware, it can be altered to fit the needs

of a particular system.

HCS360

FIGURE 7-3: SYNCHRONIZATION WINDOW

Blocked

Entire Window

rotates to eliminate

use of previously

used codes

Single Operation

Window

(32K Codes)

(16 Codes)

Double Operation

(resynchronization)

Window

(32K Codes)

Stored

Synchronization

Counter Value

HCS360

8.0 DEVELOPMENT SUPPORT

The PIC® microcontrollers and dsPIC® digital signal

controllers are supported with a full range of software

and hardware development tools:

• Integrated Development Environment

-MPLAB

® IDE Software

• Compilers/Assemblers/Linkers

- MPLAB C Compiler for Various Device

Families

- HI-TECH C for Various Device Families

- MPASMTM Assembler

-MPLINK

TM Object Linker/

MPLIBTM Object Librarian

- MPLAB Assembler/Linker/Librarian for

Various Device Families

• Simulators

- MPLAB SIM Software Simulator

•Emulators

- MPLAB REAL ICE™ In-Circuit Emulator

• In-Circuit Debuggers

- MPLAB ICD 3

- PICkit™ 3 Debug Express

• Device Programmers

- PICkit™ 2 Programmer

- MPLAB PM3 Device Programmer

• Low-Cost Demonstration/Development Boards,

Evaluation Kits, and Starter Kits

8.1 MPLAB Integrated Development

Environment Software

The MPLAB IDE software brings an ease of software

development previously unseen in the 8/16/32-bit

microcontroller market. The MPLAB IDE is a Windows®

operating system-based application that contains:

• A single graphical interface to all debugging tools

- Simulator

- Programmer (sold separately)

- In-Circuit Emulator (sold separately)

- In-Circuit Debugger (sold separately)

• A full-featured editor with color-coded context

• A multiple project manager

• Customizable data windows with direct edit of

contents

• High-level source code debugging

• Mouse over variable inspection

• Drag and drop variables from source to watch

windows

• Extensive on-line help

• Integration of select third party tools, such as

IAR C Compilers

The MPLAB IDE allows you to:

• Edit your source files (either C or assembly)

• One-touch compile or assemble, and download to

emulator and simulator tools (automatically

updates all project information)

• Debug using:

- Source files (C or assembly)

- Mixed C and assembly

- Machine code

MPLAB IDE supports multiple debugging tools in a

single development paradigm, from the cost-effective

simulators, through low-cost in-circuit debuggers, to

full-featured emulators. This eliminates the learning

curve when upgrading to tools with increased flexibility

and power.

HCS360

8.2 MPLAB C Compilers for Various

Device Families

The MPLAB C Compiler code development systems

are complete ANSI C compilers for Microchip’s PIC18,

PIC24 and PIC32 families of microcontrollers and the

dsPIC30 and dsPIC33 families of digital signal control-

lers. These compilers provide powerful integration

capabilities, superior code optimization and ease of

use.

For easy source level debugging, the compilers provide

symbol information that is optimized to the MPLAB IDE

debugger.

8.3 HI-TECH C for Various Device

Families

The HI-TECH C Compiler code development systems

are complete ANSI C compilers for Microchip’s PIC

family of microcontrollers and the dsPIC family of digital

signal controllers. These compilers provide powerful

integration capabilities, omniscient code generation

and ease of use.

For easy source level debugging, the compilers provide

symbol information that is optimized to the MPLAB IDE

debugger.

The compilers include a macro assembler, linker, pre-

processor, and one-step driver, and can run on multiple

platforms.

8.4 MPASM Assembler

The MPASM Assembler is a full-featured, universal

macro assembler for PIC10/12/16/18 MCUs.

The MPASM Assembler generates relocatable object

files for the MPLINK Object Linker, Intel® standard HEX

files, MAP files to detail memory usage and symbol

reference, absolute LST files that contain source lines

and generated machine code and COFF files for

debugging.

The MPASM Assembler features include:

• Integration into MPLAB IDE projects

• User-defined macros to streamline

assembly code

• Conditional assembly for multi-purpose

source files

• Directives that allow complete control over the

assembly process

8.5 MPLINK Object Linker/

MPLIB Object Librarian

The MPLINK Object Linker combines relocatable

objects created by the MPASM Assembler and the

MPLAB C18 C Compiler. It can link relocatable objects

from precompiled libraries, using directives from a

linker script.

The MPLIB Object Librarian manages the creation and

modification of library files of precompiled code. When

a routine from a library is called from a source file, only

the modules that contain that routine will be linked in

with the application. This allows large libraries to be

used efficiently in many different applications.

The object linker/library features include:

• Efficient linking of single libraries instead of many

smaller files

• Enhanced code maintainability by grouping

related modules together

• Flexible creation of libraries with easy module

listing, replacement, deletion and extraction

8.6 MPLAB Assembler, Linker and

Librarian for Various Device

Families

MPLAB Assembler produces relocatable machine

code from symbolic assembly language for PIC24,

PIC32 and dsPIC devices. MPLAB C Compiler uses

the assembler to produce its object file. The assembler

generates relocatable object files that can then be

archived or linked with other relocatable object files and

archives to create an executable file. Notable features

of the assembler include:

• Support for the entire device instruction set

• Support for fixed-point and floating-point data

• Command line interface

• Rich directive set

• Flexible macro language

• MPLAB IDE compatibility

HCS360

8.7 MPLAB SIM Software Simulator

The MPLAB SIM Software Simulator allows code

development in a PC-hosted environment by simulat-

ing the PIC® MCUs and dsPIC® DSCs on an instruction

level. On any given instruction, the data areas can be

examined or modified and stimuli can be applied from

a comprehensive stimulus controller. Registers can be

logged to files for further run-time analysis. The trace

buffer and logic analyzer display extend the power of

the simulator to record and track program execution,

actions on I/O, most peripherals and internal registers.

The MPLAB SIM Software Simulator fully supports

symbolic debugging using the MPLAB C Compilers,

and the MPASM and MPLAB Assemblers. The soft-

ware simulator offers the flexibility to develop and

debug code outside of the hardware laboratory envi-

ronment, making it an excellent, economical software

development tool.

8.8 MPLAB REAL ICE In-Circuit

Emulator System

MPLAB REAL ICE In-Circuit Emulator System is

Microchip’s next generation high-speed emulator for

Microchip Flash DSC and MCU devices. It debugs and

programs PIC® Flash MCUs and dsPIC® Flash DSCs

with the easy-to-use, powerful graphical user interface of

the MPLAB Integrated Development Environment (IDE),

included with each kit.

The emulator is connected to the design engineer’s PC

using a high-speed USB 2.0 interface and is connected

to the target with either a connector compatible with in-

circuit debugger systems (RJ11) or with the new high-

speed, noise tolerant, Low-Voltage Differential Signal

(LVDS) interconnection (CAT5).

The emulator is field upgradable through future firmware

downloads in MPLAB IDE. In upcoming releases of

MPLAB IDE, new devices will be supported, and new

features will be added. MPLAB REAL ICE offers

significant advantages over competitive emulators

including low-cost, full-speed emulation, run-time

variable watches, trace analysis, complex breakpoints, a

ruggedized probe interface and long (up to three meters)

interconnection cables.

8.9 MPLAB ICD 3 In-Circuit Debugger

System

MPLAB ICD 3 In-Circuit Debugger System is Micro-

chip's most cost effective high-speed hardware

debugger/programmer for Microchip Flash Digital Sig-

nal Controller (DSC) and microcontroller (MCU)

devices. It debugs and programs PIC® Flash microcon-

trollers and dsPIC® DSCs with the powerful, yet easy-

to-use graphical user interface of MPLAB Integrated

Development Environment (IDE).

The MPLAB ICD 3 In-Circuit Debugger probe is con-

nected to the design engineer's PC using a high-speed

USB 2.0 interface and is connected to the target with a

connector compatible with the MPLAB ICD 2 or MPLAB

REAL ICE systems (RJ-11). MPLAB ICD 3 supports all

MPLAB ICD 2 headers.

8.10 PICkit 3 In-Circuit Debugger/

Programmer and

PICkit 3 Debug Express

The MPLAB PICkit 3 allows debugging and program-

ming of PIC® and dsPIC® Flash microcontrollers at a

most affordable price point using the powerful graphical

user interface of the MPLAB Integrated Development

Environment (IDE). The MPLAB PICkit 3 is connected

to the design engineer's PC using a full speed USB

interface and can be connected to the target via an

Microchip debug (RJ-11) connector (compatible with

MPLAB ICD 3 and MPLAB REAL ICE). The connector

uses two device I/O pins and the reset line to imple-

ment in-circuit debugging and In-Circuit Serial Pro-

gramming™.

The PICkit 3 Debug Express include the PICkit 3, demo

board and microcontroller, hookup cables and CDROM

with user’s guide, lessons, tutorial, compiler and

MPLAB IDE software.

HCS360

8.11 PICkit 2 Development

Programmer/Debugger and

PICkit 2 Debug Express

The PICkit™ 2 Development Programmer/Debugger is

a low-cost development tool with an easy to use inter-

face for programming and debugging Microchip’s Flash

families of microcontrollers. The full featured

Windows® programming interface supports baseline

(PIC10F, PIC12F5xx, PIC16F5xx), midrange

(PIC12F6xx, PIC16F), PIC18F, PIC24, dsPIC30,

dsPIC33, and PIC32 families of 8-bit, 16-bit, and 32-bit

microcontrollers, and many Microchip Serial EEPROM

products. With Microchip’s powerful MPLAB Integrated

Development Environment (IDE) the PICkit™ 2

enables in-circuit debugging on most PIC® microcon-

trollers. In-Circuit-Debugging runs, halts and single

steps the program while the PIC microcontroller is

embedded in the application. When halted at a break-

point, the file registers can be examined and modified.

The PICkit 2 Debug Express include the PICkit 2, demo

board and microcontroller, hookup cables and CDROM

with user’s guide, lessons, tutorial, compiler and

MPLAB IDE software.

8.12 MPLAB PM3 Device Programmer

The MPLAB PM3 Device Programmer is a universal,

CE compliant device programmer with programmable

voltage verification at VDDMIN and VDDMAX for

maximum reliability. It features a large LCD display

(128 x 64) for menus and error messages and a modu-

lar, detachable socket assembly to support various

package types. The ICSP™ cable assembly is included

as a standard item. In Stand-Alone mode, the MPLAB

PM3 Device Programmer can read, verify and program

PIC devices without a PC connection. It can also set

code protection in this mode. The MPLAB PM3

connects to the host PC via an RS-232 or USB cable.

The MPLAB PM3 has high-speed communications and

optimized algorithms for quick programming of large

memory devices and incorporates an MMC card for file

storage and data applications.

8.13 Demonstration/Development

Boards, Evaluation Kits, and

Starter Kits

A wide variety of demonstration, development and

evaluation boards for various PIC MCUs and dsPIC

DSCs allows quick application development on fully func-

tional systems. Most boards include prototyping areas for

adding custom circuitry and provide application firmware

and source code for examination and modification.

The boards support a variety of features, including LEDs,

temperature sensors, switches, speakers, RS-232

interfaces, LCD displays, potentiometers and additional

EEPROM memory.

The demonstration and development boards can be

used in teaching environments, for prototyping custom

circuits and for learning about various microcontroller

applications.

In addition to the PICDEM™ and dsPICDEM™ demon-

stration/development board series of circuits, Microchip

has a line of evaluation kits and demonstration software

for analog filter design, KEELOQ® security ICs, CAN,

IrDA®, PowerSmart battery management, SEEVAL®

evaluation system, Sigma-Delta ADC, flow rate

sensing, plus many more.

Also available are starter kits that contain everything

needed to experience the specified device. This usually

includes a single application and debug capability, all

on one board.

Check the Microchip web page (www.microchip.com)

for the complete list of demonstration, development

and evaluation kits.

HCS360

9.0 ELECTRICAL CHARACTERISTICS

TABLE 9-1: ABSOLUTE MAXIMUM RATINGS

TABLE 9-2: DC CHARACTERISTICS

Symbol Item Rating Units

VDD Supply voltage -0.3 to 6.9 V

VIN Input voltage -0.3 to VDD + 0.3 V

VOUT Output voltage -0.3 to VDD + 0.3 V

IOUT Max output current 25 mA

TSTG Storage temperature -55 to +125 °C (Note)

TLSOL Lead soldering temp 300 °C (Note)

VESD ESD rating 4000 V

Note: Stresses above those listed under “ABSOLUTE MAXIMUM RATINGS” may cause permanent damage to the

device.

Commercial (C): Tamb = 0°C to +70°C

Industrial (I): Tamb = -40°C to +85°C

2.0V < VDD < 3.3 3.0 < VDD < 6.6

Parameter Sym. Min Typ1Max Min Typ1Max Unit Conditions

Operating current

(avg)

ICC 0.3 1.2

0.7 1.6

mA VDD = 3.3V

VDD = 6.6V

Standby current ICCS 0.1 1.0 0.1 1.0 μA

Auto-shutoff

current2,3

ICCS 40 75 160 350 μA

High level input

voltage

VIH 0.55 VDD VDD+0.3 0.55VDD VDD+0.3 V

Low level input

voltage

VIL -0.3 0.15 VDD -0.3 0.15VDD V

High level output

voltage

VOH 0.7 VDD 0.7VDD VIOH = -1.0 mA, VDD = 2.0V

IOH = -2.0 mA, VDD = 6.6V

Low level output

voltage

VOL 0.08 VDD 0.08VDD VIOL = 1.0 mA, VDD = 2.0V

IOL = 2.0 mA, VDD = 6.6V

LED sink current ILED 0.15 1.0 4.0 0.15 1.0 4.0 mA VLED4 = 1.5V, VDD = 6.6V

Pull-Down

Resistance; S0-S3

RS0-3 40 60 80 40 60 80 kΩVDD = 4.0V

Pull-Down

Resistance; DATA

RPWM 80 120 160 80 120 160 kΩVDD = 4.0V

Note 1: Typical values are at 25°C.

2: Auto-shutoff current specification does not include the current through the input pull-down resistors.

3: Auto-shutoff current is periodically sampled and not 100% tested.

4: VLED is the voltage between the VDD pin and the LED pin.

HCS360

FIGURE 9-1: POWER-UP AND TRANSMIT TIMING

FIGURE 9-2: POWER-UP AND TRANSMIT TIMING REQUIREMENTS

VDD = +2.0 to 6.6V

Commercial (C): Tamb = 0°C to +70°C

Industrial (I): Tamb = -40°C to +85°C

Parameter Symbol Min Max Unit Remarks

Time to second button press TBP 10 + Code

Word Time

26 + Code

Word Time

ms (Note 1)

Transmit delay from button detect TTD 4.5 26 ms (Note 2)

Debounce delay TDB 4.0 13 ms

Auto-shutoff time-out period TTO 15.0 35 s (Note 3)

Note 1: TBP is the time in which a second button can be pressed without completion of the first code word and the

intention was to press the combination of buttons.

2: Transmit delay maximum value if the previous transmission was successfully transmitted.

3: The Auto-shutoff time-out period is not tested.

Button Press

Detect

TDB

Output

TTD

Multiple Code Word Transmission

TTO

Code

Word

Code

Word

Code

Word

Code

Word

TBP

Code

Word

PWM

Input

Button

HCS360

FIGURE 9-3: PWM FORMAT SUMMARY (MOD=0)

FIGURE 9-4: PWM PREAMBLE/HEADER FORMAT (MOD=0)

FIGURE 9-5: PWM DATA FORMAT (MOD=0)

LOGIC "1"

Guard

Time

31XTEEncrypted Portion Fixed Portion

LOGIC "0"

Preamble

Header

10xTE

116

of Transmission

Preamble

50% Duty Cycle

50% Duty Cycle Preamble Header

P1 P16

31xTE10 TE Data Bits

Bit 0 Bit 1

Header

Bit 30 Bit 31 Bit 32 Bit 33 Bit 58 Bit 59

Fixed Portion of Transmission

Encrypted Portion Guard

LSB

LSB MSB MSB S3 S0 S1 S2 VLOW CRC0 CRC1

Time

Serial Number Function Code Status

Bit 60 Bit 61 Bit 62 Bit 63 Bit 64 Bit 65

CRC

Bit 66

of Transmission

HCS360

FIGURE 9-6: MANCHESTER FORMAT SUMMARY (MOD=1)

FIGURE 9-7: MANCHESTER PREAMBLE/HEADER FORMAT (MOD=1)

FIGURE 9-8: HCS360 NORMALIZED TE VS. TEMP

Guard

Preamble Header

Encrypted Portion Fixed Portion

START bit STOP bit

Time

bit 0

bit 1

bit 2

LOGIC "0"

LOGIC "1"

TETE

4XTE

31XTE

of Transmission of Transmission

Preamble

50% Duty Cycle

TPB

Preamble

Header

31 x TE

4 x TE

Bit 0 Bit 1

Data Word

Transmission

P1 P16

Preamble

50% Duty Cycle

0.8

1.7

1.6

1.5

1.4

1.3

1.2

1.1

1.0

0.9

0.7

0.6

TE Min.

TE Max.

Typical

Temperature °C

-50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90

VDD LEGEND

= 2.0V

= 3.0V

= 6.0V

HCS360

TABLE 9-3: CODE WORD TRANSMISSION TIMING PARAMETERS—PWM MODE

TABLE 9-4: CODE WORD TRANSMISSION TIMING PARAMETERS—PWM MODE

VDD = +2.0V to 6.6V

Commercial (C):Tamb = 0°C to +70°C

Industrial (I):Tamb = -40°C to +85°C

Code Words Transmitted

BSEL1 = 0

BSEL0 = 0

BSEL1 = 0

BSEL0 = 1

Symbol Characteristic Min. Typ. Max. Min. Typ. Max. Units

TEBasic pulse element 260 400 620 130 200 310 μs

TBP PWM bit pulse width 3 3 TE

TPPreamble duration 31 31 TE

THHeader duration 10 10 TE

THOP Hopping code duration 96 96 TE

TFIX Fixed code duration 105 105 TE

TGGuard Time (LNGRD = 0) 17 33 TE

— Total transmit time 259 275 TE

— Total transmit time 67.3 103.6 160.6 35.8 55.0 85.3 ms

— PWM data rate 1282 833 538 2564 1667 1075 bps

Note: The timing parameters are not tested but derived from the oscillator clock.

VDD = +2.0V to 6.6V

Commercial (C):Tamb = 0°C to +70°C

Industrial (I):Tamb = -40°C to +85°C

Code Words Transmitted

BSEL1 = 1,

BSEL0 = 0

BSEL1 = 1,

BSEL0 = 1

Symbol Characteristic Min. Typ. Max. Min. Typ. Max. Units

TEBasic pulse element 130 200 310 65 100 155 μs

TBP PWM bit pulse width 33TE

TPPreamble duration 31 31 TE

THHeader duration 10 10 TE

THOP Hopping code duration 96 96 TE

TFIX Fixed code duration 105 105 TE

TGGuard Time (LNGRD = 0) 33 65 TE

—Total transmit time 275 307 TE

—Total transmit time 35.8 55.0 85.3 20.0 30.7 47.6 ms

—PWM data rate 2564 1667 1075 5128 3333 2151 bps

Note: The timing parameters are not tested but derived from the oscillator clock.

HCS360

TABLE 9-5: CODE WORD TRANSMISSION TIMING PARAMETERS—MANCHESTER MODE

TABLE 9-6: CODE WORD TRANSMISSION TIMING PARAMETERS—MANCHESTER MODE

VDD = +2.0V to 6.6V

Commercial (C):Tamb = 0°C to +70°C

Industrial (I):Tamb = -40°C to +85°C

Code Words Transmitted

BSEL1 = 0,

BSEL0 = 0

BSEL1 = 0.

BSEL0 = 1

Symbol Characteristic Min. Typ. Max. Min. Typ. Max. Units

TEBasic pulse element 520 800 1240 260 400 620 μs

TPPreamble duration 31 31 TE

THHeader duration 4 4 TE

TSTART START bit 2 2 TE

THOP Hopping code duration 64 64 TE

TFIX Fixed code duration 70 70 TE

TSTOP STOP bit 2 2 TE

TGGuard Time (LNGRD = 0) 9 17 TE

— Total transmit time 182 190 TE

— Total transmit time 94.6 145.6 223.7 49.4 76.0 117.8 ms

— Manchester data rate 1923 1250 806 3846.2 2500 1612.9 bps

Note: The timing parameters are not tested but derived from the oscillator clock.

VDD = +2.0V to 6.6V

Commercial (C):Tamb = 0°C to +70°C

Industrial (I):Tamb = -40°C to +85°C

Code Words Transmitted

BSEL1 = 1,

BSEL0 = 0

BSEL1 = 1.

BSEL0 = 1

Symbol Characteristic Min. Typ. Max. Min. Typ. Max. Units

EBasic pulse element 260 400 620 130 200 310 μs

TPPreamble duration 32 32 TE

THHeader duration 44TE

TSTART START bit 22TE

THOP Hopping code duration 64 64 TE

TFIX Fixed code duration 70 70 TE

TSTOP STOP bit 22TE

TGGuard Time (LNGRD = 0) 16 32 TE

—Total transmit time 190 206 TE

—Total transmit time 49.4 76.0 117.8 26.8 41.2 63.4 ms

—Manchester data rate 3846.2 2500.0 1612.9 7692.3 5000.0 3225.8 bps

Note: The timing parameters are not tested but derived from the oscillator clock.

HCS360

10.0 PACKAGING INFORMATION

10.1 Package Marking Information

8-Lead PDIP Example

8-Lead SOIC Example

XXXXXXXX

XXXXXNNN

YYWW

HCS360

XXXXXNNN

0025

XXXXXXX

XXXYYWW

NNN

HCS360

XXX0025

NNN

Legend: XX...X Customer specific information*

Y Year code (last digit of calendar year)

YY Year code (last 2 digits of calendar year)

WW Week code (week of January 1 is week ‘01’)

NNN Alphanumeric traceability code

Note: In the event the full Microchip part number cannot be marked on one line, it will

be carried over to the next line thus limiting the number of available characters

for customer specific information.

*Standard PIC MCU device marking consists of Microchip part number, year code, week code, and

traceability code. For PIC MCU device marking beyond this, certain price adders apply. Please check

with your Microchip Sales Office. For QTP devices, any special marking adders are included in QTP

price.

HCS360

10.2 Package Details





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 

 

 



 



 

   

  

  

    

    

    

    

    

    

    

    

    

    

    

NOTE 1

   

HCS360

Note: For the most current package drawings, please see the Microchip Packaging Specification located at

http://www.microchip.com/packaging

HCS360

Note: For the most current package drawings, please see the Microchip Packaging Specification located at

http://www.microchip.com/packaging

HCS360

 ! ""#$%& !'



HCS360

APPENDIX A: ADDITIONAL

INFORMATION

Microchip’s Secure Data Products are covered by

some or all of the following:

Code hopping encoder patents issued in European

countries and U.S.A.

Secure learning patents issued in European countries,

U.S.A. and R.S.A.

REVISION HISTORY

Revision F (June 2011)

• Updated the following sections: Development Sup-

port, The Microchip Web Site, Reader Response

and HCS360 Product Identification System

• Added new section Appendix A

• Minor formatting and text changes were incorporated

throughout the document

HCS360

THE MICROCHIP WEB SITE

Microchip provides online support via our WWW site at

www.microchip.com. This web site is used as a means

to make files and information easily available to

customers. Accessible by using your favorite Internet

browser, the web site contains the following

information:

•Product Support – Data sheets and errata,

application notes and sample programs, design

resources, user’s guides and hardware support

documents, latest software releases and archived

software

•General Technical Support – Frequently Asked

Questions (FAQ), technical support requests,

online discussion groups, Microchip consultant

program member listing

•Business of Microchip – Product selector and

ordering guides, latest Microchip press releases,

listing of seminars and events, listings of

Microchip sales offices, distributors and factory

representatives

CUSTOMER CHANGE NOTIFICATION

SERVICE

Microchip’s customer notification service helps keep

customers current on Microchip products. Subscribers

will receive e-mail notification whenever there are

changes, updates, revisions or errata related to a

specified product family or development tool of interest.

To register, access the Microchip web site at

www.microchip.com. Under “Support”, click on

“Customer Change Notification” and follow the

registration instructions.

CUSTOMER SUPPORT

Users of Microchip products can receive assistance

through several channels:

• Distributor or Representative

• Local Sales Office

• Field Application Engineer (FAE)

• Technical Support

• Development Systems Information Line

Customers should contact their distributor,

representative or field application engineer (FAE) for

support. Local sales offices are also available to help

customers. A listing of sales offices and locations is

included in the back of this document.

Technical support is available through the web site

at: http://microchip.com/support

HCS360

READER RESPONSE

It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip

product. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our

documentation can better serve you, please FAX your comments to the Technical Publications Manager at

(480) 792-4150.

Please list the following information, and use this outline to provide us with your comments about this document.

TO: Technical Publications Manager

RE: Reader Response

Total Pages Sent ________

From: Name

Company

Address

City / State / ZIP / Country

Telephone: (_______) _________ - _________

Application (optional):

Would you like a reply? Y N

Device: Literature Number:

Questions:

FAX: (______) _________ - _________

DS40152FHCS360

1. What are the best features of this document?

2. How does this document meet your hardware and software development needs?

3. Do you find the organization of this document easy to follow? If not, why?

4. What additions to the document do you think would enhance the structure and subject?

5. What deletions from the document could be made without affecting the overall usefulness?

6. Is there any incorrect or misleading information (what and where)?

7. How would you improve this document?

HCS360

HCS360 PRODUCT IDENTIFICATION SYSTEM

To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.

Package: P=Plastic DIP (300 mil Body), 8-lead

SN = Plastic SOIC (150 mil Body), 8-lead

Temperature Blank = 0°C to +70°C

Range: I=–40°C to +85°C

Device: HCS360 Code Hopping Encoder

HCS360T Code Hopping Encoder (Tape and Reel)

HCS360 — /P

Information contained in this publication regarding device

applications and the like is provided only for your convenience

and may be superseded by updates. It is your responsibility to

ensure that your application meets with your specifications.

MICROCHIP MAKES NO REPRESENTATIONS OR

WARRANTIES OF ANY KIND WHETHER EXPRESS OR

IMPLIED, WRITTEN OR ORAL, STATUTORY OR

OTHERWISE, RELATED TO THE INFORMATION,

INCLUDING BUT NOT LIMITED TO ITS CONDITION,

QUALITY, PERFORMANCE, MERCHANTABILITY OR

FITNESS FOR PURPOSE. Microchip disclaims all liability

arising from this information and its use. Use of Microchip

devices in life support and/or safety applications is entirely at

the buyer’s risk, and the buyer agrees to defend, indemnify and

hold harmless Microchip from any and all damages, claims,

suits, or expenses resulting from such use. No licenses are

conveyed, implicitly or otherwise, under any Microchip

intellectual property rights.

Trademarks

The Microchip name and logo, the Microchip logo, dsPIC,

KEELOQ, KEELOQ logo, MPLAB, PIC, PICmicro, PICSTART,

PIC32 logo, rfPIC and UNI/O are registered trademarks of

Microchip Technology Incorporated in the U.S.A. and other

countries.

FilterLab, Hampshire, HI-TECH C, Linear Active Thermistor,

MXDEV, MXLAB, SEEVAL and The Embedded Control

Solutions Company are registered trademarks of Microchip

Technology Incorporated in the U.S.A.

Analog-for-the-Digital Age, Application Maestro, CodeGuard,

dsPICDEM, dsPICDEM.net, dsPICworks, dsSPEAK, ECAN,

ECONOMONITOR, FanSense, HI-TIDE, In-Circuit Serial

Programming, ICSP, Mindi, MiWi, MPASM, MPLAB Certified

logo, MPLIB, MPLINK, mTouch, Omniscient Code

Generation, PICC, PICC-18, PICDEM, PICDEM.net, PICkit,

PICtail, REAL ICE, rfLAB, Select Mode, Total Endurance,

TSHARC, UniWinDriver, WiperLock and ZENA are

trademarks of Microchip Technology Incorporated in the

U.S.A. and other countries.

SQTP is a service mark of Microchip Technology Incorporated

in the U.S.A.

All other trademarks mentioned herein are property of their

respective companies.

Printed on recycled paper.

ISBN: 978-1-61341-224-4

Note the following details of the code protection feature on Microchip devices:

• Microchip products meet the specification contained in their particular Microchip Data Sheet.

• Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the

intended manner and under normal conditions.

• There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our

knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data

Sheets. Most likely, the person doing so is engaged in theft of intellectual property.

• Microchip is willing to work with the customer who is concerned about the integrity of their code.

• Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not

mean that we are guaranteeing the product as “unbreakable.”

Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our

products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts

allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.

Microchip received ISO/TS-16949:2002 certification for its worldwide

headquarters, design and wafer fabrication facilities in Chandler and

Tempe, Arizona; Gresham, Oregon and design centers in California

and India. The Company’s quality system processes and procedures

are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping

devices, Serial EEPROMs, microperipherals, nonvolatile memory and

analog products. In addition, Microchip’s quality system for the design

and manufacture of development systems is ISO 9001:2000 certified.

AMERICAS

Corporate Office

2355 West Chandler Blvd.

Chandler, AZ 85224-6199

Tel: 480-792-7200

Fax: 480-792-7277

Technical Support:

http://www.microchip.com/

support

Web Address:

www.microchip.com

Atlanta

Duluth, GA

Tel: 678-957-9614

Fax: 678-957-1455

Boston

Westborough, MA

Tel: 774-760-0087

Fax: 774-760-0088

Chicago

Itasca, IL

Tel: 630-285-0071

Fax: 630-285-0075

Cleveland

Independence, OH

Tel: 216-447-0464

Fax: 216-447-0643

Dallas

Addison, TX

Tel: 972-818-7423

Fax: 972-818-2924

Detroit

Farmington Hills, MI

Tel: 248-538-2250

Fax: 248-538-2260

Indianapolis

Noblesville, IN

Tel: 317-773-8323

Fax: 317-773-5453

Los Angeles

Mission Viejo, CA

Tel: 949-462-9523

Fax: 949-462-9608

Santa Clara

Santa Clara, CA

Tel: 408-961-6444

Fax: 408-961-6445

Toronto

Mississauga, Ontario,

Canada

Tel: 905-673-0699

Fax: 905-673-6509

ASIA/PACIFIC

Asia Pacific Office

Suites 3707-14, 37th Floor

Tower 6, The Gateway

Harbour City, Kowloon

Hong Kong

Tel: 852-2401-1200

Fax: 852-2401-3431

Australia - Sydney

Tel: 61-2-9868-6733

Fax: 61-2-9868-6755

China - Beijing

Tel: 86-10-8569-7000

Fax: 86-10-8528-2104

China - Chengdu

Tel: 86-28-8665-5511

Fax: 86-28-8665-7889

China - Chongqing

Tel: 86-23-8980-9588

Fax: 86-23-8980-9500

China - Hangzhou

Tel: 86-571-2819-3180

Fax: 86-571-2819-3189

China - Hong Kong SAR

Tel: 852-2401-1200

Fax: 852-2401-3431

China - Nanjing

Tel: 86-25-8473-2460

Fax: 86-25-8473-2470

China - Qingdao

Tel: 86-532-8502-7355

Fax: 86-532-8502-7205

China - Shanghai

Tel: 86-21-5407-5533

Fax: 86-21-5407-5066

China - Shenyang

Tel: 86-24-2334-2829

Fax: 86-24-2334-2393

China - Shenzhen

Tel: 86-755-8203-2660

Fax: 86-755-8203-1760

China - Wuhan

Tel: 86-27-5980-5300

Fax: 86-27-5980-5118

China - Xian

Tel: 86-29-8833-7252

Fax: 86-29-8833-7256

China - Xiamen

Tel: 86-592-2388138

Fax: 86-592-2388130

China - Zhuhai

Tel: 86-756-3210040

Fax: 86-756-3210049

ASIA/PACIFIC

India - Bangalore

Tel: 91-80-3090-4444

Fax: 91-80-3090-4123

India - New Delhi

Tel: 91-11-4160-8631

Fax: 91-11-4160-8632

India - Pune

Tel: 91-20-2566-1512

Fax: 91-20-2566-1513

Japan - Yokohama

Tel: 81-45-471- 6166

Fax: 81-45-471-6122

Korea - Daegu

Tel: 82-53-744-4301

Fax: 82-53-744-4302

Korea - Seoul

Tel: 82-2-554-7200

Fax: 82-2-558-5932 or

82-2-558-5934

Malaysia - Kuala Lumpur

Tel: 60-3-6201-9857

Fax: 60-3-6201-9859

Malaysia - Penang

Tel: 60-4-227-8870

Fax: 60-4-227-4068

Philippines - Manila

Tel: 63-2-634-9065

Fax: 63-2-634-9069

Singapore

Tel: 65-6334-8870

Fax: 65-6334-8850

Taiwan - Hsin Chu

Tel: 886-3-6578-300

Fax: 886-3-6578-370

Taiwan - Kaohsiung

Tel: 886-7-213-7830

Fax: 886-7-330-9305

Taiwan - Taipei

Tel: 886-2-2500-6610

Fax: 886-2-2508-0102

Thailand - Bangkok

Tel: 66-2-694-1351

Fax: 66-2-694-1350

EUROPE

Austria - Wels

Tel: 43-7242-2244-39

Fax: 43-7242-2244-393

Denmark - Copenhagen

Tel: 45-4450-2828

Fax: 45-4485-2829

France - Paris

Tel: 33-1-69-53-63-20

Fax: 33-1-69-30-90-79

Germany - Munich

Tel: 49-89-627-144-0

Fax: 49-89-627-144-44

Italy - Milan

Tel: 39-0331-742611

Fax: 39-0331-466781

Netherlands - Drunen

Tel: 31-416-690399

Fax: 31-416-690340

Spain - Madrid

Tel: 34-91-708-08-90

Fax: 34-91-708-08-91

UK - Wokingham

Tel: 44-118-921-5869

Fax: 44-118-921-5820

Worldwide Sales and Service

05/02/11