M67204E
Rev. G – June 5, 2000 1
Introduction
The M67204E implement a first-in first-out algorithm,
featuring asynchronous read/write operations. The FULL
and EMPTY flags prevent data overflow and underflow.
The Expansion logic allows unlimited expansion in word
size and depth with no timing penalties. Twin address
pointers automatically generate internal read and write
addresses, and no external address information are
required for the TEMIC FIFOs. Address pointers are
automatically incremented with the write pin and read
pin. The 9 bits wide data are used in data communications
applications where a parity bit for error checking is
necessary. The Retransmit pin resets the Read pointer to
zero without affecting the write pointer. This is very
useful for retransmitting data when an error is detected in
the system.
Using an array of eigh transistors (8 T) memory cell, the
M67204E combine an extremely low standby supply
current (typ = 1.0 µA) with a fast access time at 40 ns
over the full temperature range. All versions offer battery
backup data retention capability with a typical power
consumption at less than 2 µW.
The M67204E is processed according to the methods of
the latest revision of the MIL STD 883 (class B or S), ESA
SCC 9000 and QML.
Features
DFirst-in first-out dual port memory
D4096 × 9 organisation
DFast access time: 40, 50 ns
DWide temperature range : – 55 °C to + 125 °C
DFully expandable by word width or depth
DAsynchronous read/write operations
DEmpty, full and half flags in single device mode
DRetransmit capability
DBi-directional applications
DBattery back-up operation 2 V data retention
DTTL compatible
DSingle 5 V ± 10 % power supply
DHigh performance SCMOS technology
4 K 9 CMOS Parallel FIFO Rad Tolerant
M67204E
Rev. G June 5, 2000
2
Interface
Block Diagram
Pin Configuration
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
W
I8
I3
I2
I1
I0
XI
FF
Q0
Q1
Q2
Q3
Q8
GND
VCC
I4
I5
I6
I7
FL/RT
RS
EF
XO/HF
Q7
Q6
Q5
Q4
R
DIL ceramic 28 pin 300 mils
FP 28 pin 400 mils
(top view)
M67204E
Rev. G June 5, 2000 3
Pin Names
NAMES DESCRIPTION
I08 Inputs
Q08 Outputs
WWrite Enable
RRead Enable
RS Reset
EF Empty Flag
NAMES DESCRIPTION
FF Full Flag
XO/HF Expansion Out/Half-Full Flag
XI Expansion IN
FL/RT First Load/Retransmit
VCC Power Supply
GND Ground
Signal Description
Data In (I0 - I8)
Data inputs for 9-bit data
Reset (RS)
Reset occurs whenever the Reset (RS) input is taken to a
low state. Reset returns both internal read and write
pointers to the first location. A reset is required after
power-up before a write operation can be enabled. Both
the Read Enable (R) and W rite Enable (W) inputs must be
in the high state during the period shown in figure 1 (i.e.
tRSS before the rising edge of RS) and should not change
until tRSR after the rising edge of RS. The Half-Full Flag
(HF) will be reset to high after Reset (RS).
Figure 1. Reset.
Notes : 1. EF, FF and HF may change status during reset, but flags will be valid at tRSC.
2. W and R = VIH around the rising edge of RS.
Write Enable (W)
A write cycle is initiated on the falling edge of this input
if the Full Flag (FF) is not set. Data set-up and hold times
must be maintained in the rise time of the leading edge of
the Write Enable (W). Data is stored sequentially in the
Ram array, regardless of any current read operation.
Once half of the memory is filled, and during the falling
edge of the next write operation, the Half-Full Flag (HF)
will be set to low and remain in this state until the
difference between the write and read pointers is less than
or equal to half of the total available memory in the
device. The Half-Full Flag (HF) is then reset by the rising
edge of the read operation.
To prevent data overflow, the Full Flag (FF) will go low,
inhibiting further write operations. On completion of a
valid read operation, the Full Flag (FF) will go high after
TRFF, allowing a valid write to begin. When the FIFO
stack is full, the internal write pointer is blocked from W,
so that external changes to W will have no effect on the
full FIFO stack.
M67204E
Rev. G June 5, 2000
4
Read Enable (R)
A read cycle is initiated on the falling edge of the Read
Enable (R) provided that the Empty Flag (EF) is not set.
The data is accessed on a first in/first out basis, not with
standing any current write operations. After Read Enable
(R) goes high, the Data Outputs (Q0 Q8) will return to
a high impedance state until the next Read operation.
When all the data in the FIFO stack has been read, the
Empty Flag (EF) will go low, allowing the final read
cycle, but inhibiting further read operations whilst the
data outputs remain in a high impedance state. Once a
valid write operation has been completed, the Empty Flag
(EF) will go high after tWEF and a valid read may then
be initiated. When the FIFO stack is empty, the internal
read pointer is blocked from R, so that external changes
to R will have no effect on the empty FIFO stack.
First Load/Retransmit (FL/RT)
This is a dual-purpose input. In the Depth Expansion
Mode, this pin is connected to ground to indicate that it
is the first loaded (see Operating Modes). In the Single
Device Mode, this pin acts as the retransmit input. The
Single Device Mode is initiated by connecting the
Expansion In (XI) to ground.
The M67204E can be made to retransmit data when the
Retransmit Enable Control (RT) input is pulsed low. A
retransmit operation will set the internal read point to the
first location and will not affect the write pointer. Read
Enable (R) and W rite Enable (W) must be in the high state
during retransmit. The retransmit feature is intended for
use when a number of writes equals to or less than the
depth of the FIFO have occured since the last RS cycle.
The retransmit feature is not compatible with the Depth
Expansion Mode and will affect the Half-Full Flag (HF),
in accordance with the relative locations of the read and
write pointers.
Expansion In (XI)
This input is a dual-purpose pin. Expansion In (XI )is
connected to GND to indicate an operation in the single
device mode. Expansion In (XI) is connected to
Expansion Out (XO) of the previous device in the Depth
Expansion or Daisy Chain modes.
Full Flag (FF)
The Full Flag (FF) will go low, inhibiting further write
operations when the write pointer is one location less than
the read pointer, indicating that the device is full. If the
read pointer is not moved after Reset (RS), the Full Flag
(FF) will go low after 4096 writes.
Empty Flag (EF)
The Empty Flag (EF) will go low, inhibiting further read
operations when the read pointer is equal to the write
pointer, indicating that the device is empty.
Expansion Out/Half-full Flag (XO/HF)
This is a dual-purpose output. In the single device mode,
when Expansion In (XI) is connected to ground, this
output acts as an indication of a half-full memory.
After half the memory is filled and on the falling edge of
the next write operation, the Half-Full Flag (HF) will be
set to low and will remain set until the difference between
the write and read pointers is less than or equal to half of
the total memory of the device. The Half-Full Flag (HF)
is then reset by the rising edge of the read operation.
In the Depth Expansion Mode, Expansion In (XI) is
connected to Expansion Out (XO) of the previous device.
This output acts as a signal to the next device in the Daisy
Chain by providing a pulse to the next device when the
previous device reaches the last memory location.
Data Output (Q0 – Q8)
DATA output for 9-bit wide data. This data is in a high
impedance condition whenever Read (R) is in a high state.
M67204E
Rev. G June 5, 2000 5
Functional Description
Operating Modes
Single Device Mode
A single M67204E may be used when the application
requirements are for 4096 words or less. The M67204E is
in a Single Device Configuration when the Expansion In
(XI) control input is grounded (see Figure 2). In this mode
the Half-Full Flag (HF), which is an active low output, is
shared with Expansion Out (XO).
Figure 2. Block Diagram of Single 4K × 9 FIFO.
(HALF–FULL FLAG)
WRITE (W)(R) READ
DATAIN
9
(I) DATAOUT
9
(Q)
FULL FLAG
RESET
(FF)
(RS)
EMPTY FLAG
RETRANSMIT
(EF)
(RT)
EXPANSION IN (XI)
HF
M
67204E
Width Expansion Mode
Word width may be increased simply by connecting the
corresponding input control signals of multiple devices.
Status flags (EF, FF and HF) can be detected from any
device. Figure 3 demonstrates an 18-bit word width by
using two M67204E. Any word width can be attained by
adding additional M67204E.
Figure 3. Block Diagram of 4096 × 18 FIFO Memory Used in Width Expansion Mode.
M
67204E
XI
M
67204E
XI
(W)WRITE
(FF)
FULL FLAG
RESET
(R) READ
(EF) EMPTY FLAG
(RT) RETRANSMIT
HF
9
18
(RS) 9
18
9
DATAIN (I)
9HF
(Q) DATAOUT
Note : 3. Flag detection is accomplished by monitoring the FF, EF and the HF signals on either (any) device used in the width
expansion configuration. Do not connect any output control signals together.
M67204E
Rev. G June 5, 2000
6
Table 1 : Reset and retransmit
Single Device Configuration/Width Expansion Mode
INPUTS INTERNAL STATUS OUTPUTS
MODE RS RT XI Read Pointer Write Pointer EF FF HF
Reset 0 X 0 Location Zero Location Zero 0 1 1
Retransmit 1 0 0 Location Zero Unchanged X X X
Read/Write 1 1 0 Increment(4) Increment(4) X X X
Note : 4. Pointer will increment if flag is high.
Table 2 : Reset and First Load Truth Table
Depth Expansion/Compound Expansion Mode
INPUTS INTERNAL STATUS OUTPUTS
MODE RS FL XI Read Pointer Write Pointer EF FF
Reset First Device 0 0 (5) Location Zero Location Zero 0 1
Reset All Other Devices 0 1 (5) Location Zero Location Zero 0 1
Read/Write 1 X (5) X X X X
Note : 5. XI is connected to XO of previous device.
See fig. 5.
Depth Expansion (Daisy Chain) Mode
The M67204E can be easily adapted for applications
which require more than 4096 words. Figure 4
demonstrates Depth Expansion using three M67204E.
Any depth can be achieved by adding additional
M67204E.
The M67204E operate in the Depth Expansion
configuration if the following conditions are met :
1. The first device must be designated by connecting the
First Load (FL) control input to ground.
2. All other devices must have FL in the high state.
3. The Expansion Out (XO) pin of each device must be
connected to the Expansion In (XI) pin of the next
device. See figure 4.
4. External logic is needed to generate a composite Full
Flag (FF) and Empty Flag (EF). This requires that all
EFs and all FFs be ØRed (i.e. all must be set to
generate the correct composite FF or EF). See figure 4.
5. The Retransmit (RT) function and Half-Full Flag (HF)
are not available in the Depth Expansion Mode.
Compound Expansion Module
It is quite simple to apply the two expansion techniques
described above together to create large FIFO arrays (see
figure 5).
Bidirectional Mode
Applications which require data buffering between two
systems (each system being capable of Read and Write
operations) can be created by coupling M67204E as
shown in figure 6. Care must be taken to ensure that the
appropriate flag is monitored by each system (i.e. FF is
monitored on the device on which W is in use ; EF is
monitored on the device on which R is in use). Both Depth
Expansion and Width Expansion may be used in this
mode.
Data Flow - Through Modes
Two types of flow-through modes are permitted : a read
flow-through and a write flow-through mode. In the read
flow-through mode (figure 17) the FIFO stack allows a
M67204E
Rev. G June 5, 2000 7
single word to be read after one word has been written to
an empty FIFO stack. The data is enabled on the bus at
(tWEF + tA) ns after the leading edge of W which is
known as the first write edge and remains on the bus until
the R line is raised from low to high, after which the bus
will go into a three-state mode after tRHZ ns. The EF line
will show a pulse indicating temporary reset and then will
be set. In the interval in which R is low, more words may
be written to the FIFO stack (the subsequent writes after
the first write edge will reset the Empty Flag) ; however,
the same word (written on the first write edge) presented
to the output bus as the read pointer will not be
incremented if R is low. On toggling R, the remaining
words written to the FIFO will appear on the output bus
in accordance with the read cycle timings.
In the write flow-through mode (figure 18), the FIFO
stack allows a single word of data to be written
immediately after a single word of data has been read
from a full FIFO stack. The R line causes the FF to be
reset, but the W line, being low, causes it to be set again
in anticipation of a new data word. The new word is
loaded into the FIFO stack on the leading edge of W. The
W line must be toggled when FF is not set in order to write
new data into the FIFO stack and to increment the write
pointer.
Figure 4. Block Diagram of 12288 × 9 FIFO Memory (Depth expansion).
W
69FF
9
FF
9
FF
9
RS
FULL
XO
EF
FL
EF
FL
EF
FL
XI
EMPTY
9
R
VCC
Q
M
67204E
M
67204E
M
67204E
Figure 5. Compound FIFO Expansion.
M67204E
DEPTH
EXPANSION
BLOCK
M67204E
DEPTH
EXPANSION
BLOCK
M67204E
DEPTH
EXPANSION
BLOCK
R . W . RS
Q0 Q8
Q0 Q8
Q9 Q17
Q9 Q17
Q(N8) QN
Q(N8) QN
I(N8) IN
I(N8) IN
I9 I17
I0 I8
I9 I17
I0 I8
Notes : 6. For depth expansion block see section on Depth Expansion and Figure 4.
7. For Flag detection see section on Width Expansion and Figure 3.
M67204E
Rev. G June 5, 2000
8
Figure 6. Bidirectional FIFO Mode.
M
67204
M
67204
SYSTEM A SYSTEM B
WA
FFA
RB
EFB
HFB
IA 08QB 08
IB 08
QA 08
RA
HFA
EFA
WB
FFB
Electrical Characteristics
Absolute Maximum Ratings
Supply voltage (VCC GND) 0.3 V to 7.0 V. . . . . . . . . . . . . . . . . .
Input or Output voltage applied : (GND 0.3 V) to (Vcc + 0.3 V). . . .
Storage temperature : 65 °C to + 150 °C. . . . . . . . . . . . . . . . . . . . . .
OPERATING RANGE OPERATING SUPPLY VOLTAGE OPERATING TEMPERATURE
Military Vcc = 5 V ± 10 % 55 °C to + 125 °C
M67204E
Rev. G June 5, 2000 9
DC Parameters
M67204E M67204E
Parameter Description 40 50 UNIT VALUE
ICCOP (8) Operating
supply current 135 125 mA Max
ICCSB (9) Standby
supply current 1.5 1.5 mA Max
ICCPD (10) Power down
current 200 200 µA Max
Notes : 8. Icc measurements are made with outputs open. F = F max
9. R = W = RS = FL/RT = VIH.
10. All input = Vcc.
PARAMETER DESCRIPTION M67204E UNIT VALUE
ILI (11) Input leakage current ± 1 µA Max
ILO (12) Output leakage current ± 1 µA Max
VIL (13) Input low voltage 0.8 V Max
VIH (13) Input high voltage 2.2 V Min
VOL (14) Output low voltage 0.4 V Max
VOH (14) Output high voltage 2.4 V Min
C IN (15) Input capacitance 8 pF Max
C OUT (15) Output capacitance 8 pF Max
Notes : 11. 0.4 Vin Vcc.
12. R = VIH, 0.4 VOUT VCC.
13. VIH max = Vcc + 0.3 V. VIL min = 0.3 V or 1 V pulse width 50 ns
14. Vcc min, IOL = 8 mA, IOH = 2 mA.
15. Guaranteed but not tested
AC Test Conditions
Input pulse levels : Gnd to 3.0 V
Input rise/Fall times : 5 ns
Input timing reference levels : 1.5 V
Output reference levels : 1.5 V
Output load : See figure 7
Figure 7. Output Load.
TO
OUTPUT
PIN 333 30 pF*
500
5 V
* includes jig and scope capacitance or equivalent circuit
M67204E
Rev. G June 5, 2000
10
SYMBOL (16) SYMBOL (17) PARAMETER (18) (22) M67204E
40 M67204E
50 UNITSYMBOL (16) SYMBOL (17) PARAMETER (18) (22) MIN. MAX. MIN. MAX. UNIT
READ CYCLE
TRLRL tRC Read cycle time 50 65 ns
TRLQV tA Access time 40 50 ns
TRHRL tRR Read recovery time 10 15 ns
TRLRH tRPW Read pulse width (19) 40 50 ns
TRLQX tRLZ Read low to data low Z (20) 510 ns
TWHQX tWLZ Write low to data low Z (20, 21) 10 15 ns
TRHQX tDV Data valid from read high 55ns
TRHQZ tRHZ Read high to data high Z (20) 25 30 ns
WRITE CYCLE
TWLWL tWC Write cycle time 50 65 ns
TWLWH tWPW Write pulse width (19) 40 50 ns
TWHWL tWR Write recovery time 10 15 ns
TDVWH tDS Data set-up time 20 30 ns
TWHDX tDH Data hold time 00ns
RESET CYCLE
TRSLWL tRSC Reset cycle time 50 65 ns
TRSLRSH tRS Reset pulse width (19) 40 50 ns
TWHRSH tRSS Reset set-up time 40 50 ns
TRSHWL tRSR Reset recovery time 10 15 ns
RETRANSMIT CYCLE
TRTLWL tRTC Retransmit cycle time 50 65 ns
TRTLRTH tRT Retransmit pulse width (19) 40 50 ns
TWHRTH tRTS Retransmit set-up time (20) 40 50 ns
TRTHWL tRTR Retransmit recovery time 10 15 ns
FLAGS
TRSLEFL tEFL Reset to EF low 50 60 ns
TRSLFFH tHFH, tFFH Reset to HF/FF high 50 60 ns
TRLEFL tREF Read low to EF low 35 45 ns
TRHFFH tRFF Read high to FF high 35 45 ns
TEFHRH tRPE Read width after EF high 40 50 ns
TWHEFH tWEF Write high to EF high 35 45 ns
TWLFFL tWFF Write low to FF low 35 45 ns
TWLHFL tWHF Write low to HF low 50 60 ns
TRHHFH tRHF Read high to HF high 50 60 ns
TFFHWH tWPF Write width after FF high 40 50 ns
M67204E
Rev. G June 5, 2000 11
SYMBOL (16) SYMBOL (17) PARAMETER (18) (22) M67204E
40 M67204E
50 UNITSYMBOL (16) SYMBOL (17) PARAMETER (18) (22) MIN. MAX. MIN. MAX. UNIT
EXPANSION PREVIEW
TWLXOL tXOL Read/Write to XO low 40 50 ns
TWHXOH tXOH Read/Write to XO high 40 50 ns
TXILXIH tXI XI pulse width 40 50 ns
TXIHXIL tXIR XI recovery time 10 10 ns
TXILRL tXIS XI set-up time 10 15 ns
Notes : 16. STD symbol.
17. ALT symbol.
18. Timings referenced as in ac test conditions.
19. Pulse widths less than minimam value are not allowed.
20. Values guaranteed by design, not currently tested.
21. Only applies to read data flow-through mode.
22. All parameters tested only.
Figure 8. Asynchronous W rite and Read Operation.
M67204E
Rev. G June 5, 2000
12
Figure 9. Full Flag from Last Write to First Read.
Figure 10. Empty Flag from Last Read to First Write.
Figure 11. Retransmit.
Notes : 23. EF, FF and HF may change status during Retransmit, but flags will be valid at tRTC.
M67204E
Rev. G June 5, 2000 13
Figure 12. Empty Flag Timing
Figure 13. Full Flag Timing
Figure 14. Half-Full Flag Timing.
M67204E
Rev. G June 5, 2000
14
Figure 15. Expansion Out.
Figure 16. Expansion In.
Figure 17. Read Data Flow Through Mode.
M67204E
Rev. G June 5, 2000 15
Figure 18. Write Data Flow Through Mode.
Ordering Information
M
M = Military 55°to +125°C
S = Space 55°to +125°C
* For ordering in QML quality level, use the QML PIN according to SMD no 596289568.
M
M = 5 V version
DP
DP = 28 pin FP 400 mils
CP = Side brazed 28 pins 300 mils
0 = Dice form
67204EV
67204E = 4096 × 9 FIFO
EV = Very low power Rad Tolerant
40
40 ns
50 ns
TEMPERATURE RANGE PACKAGE DEVICE SPEED FLOW*
blank = MHS standards
/883 = MIL STD 883 Class B or S
SB/SC = SCC 9000 level B/C
/883
The information contained herein is subject to change without notice. No r esponsibility is assumed by TEMIC for using this publication and/or circuits
described herein : nor for any possible infringements of patents or other rights of third parties which may result from its use.