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128Mb_DDR_x4x8x16_D2.fm - 128Mb DDR: Rev. F; Core DDR: Rev. A 4/07 EN 9©2004 Micron Technology, Inc. All rights reserved.
128Mb: x4, x8, x16 DDR SDRA M
Pin Assignments and De scriptio ns
Table 4: Pin Descriptions
TSOP
Numbers Symbol Type Description
29, 30, 31
32, 35, 36,
37, 38, 39,
40, 28, 41
A0, A1, A2,
A3, A4, A5,
A6, A7, A8,
A9, A10, A11
Input Address inputs: Provide the row address for ACTIVE commands, and the
column address and auto precharge bit (A10) for READ/WRITE commands, to
select one location out of the memory array in the respective bank. A10
sampled during a PRECHARGE command determines whether the
PRECHARGE appl ies to one bank (A10 LOW, bank selected by BA0, BA1) or
all banks (A10 HIGH). The address inputs also provide the op-code during a
LOAD MODE REGISTER command.
26, 27 BA0, BA1 Input Bank addr ess inputs: BA0 and BA1 define to which bank an ACTIVE, READ,
WRITE, or PRECHARGE command is being applied. BA0 and BA1 also define
which mode register (mode register or extende d mode register) is loaded
during the LOAD MODE REGISTER command.
45, 46 CK, CK# Input Clock: CK and CK# are differential clock inputs. All address and control
input signals are sampled on the crossing of the positive edge of CK and
negative edge of CK#. Output data (DQ and DQS) is referenced to the
crossings of CK and CK#.
44 CKE Input Clock enable: CKE HIGH activates and CKE LOW deactivates the internal
clock, input buffers, and output drivers. Taking CKE LOW provides
PRECHARGE POWER-DOWN and SELF REFRESH operations (all banks idle), or
ACTIVE POWER-DOWN (row ACTIVE in any bank). CKE is synchronous for
POWER-DOWN entry and exit, and for SELF REFRESH entry. CKE is
asynchronous for SELF REFRESH exit and for disabling the ou tput s. C KE mu st
be maintained HIGH throughout read and write accesses. Input buffers
(excluding CK, CK#, and CKE) are disabled during POWER-DOWN. Input
buffers (excluding CKE) are disabled during SELF REFRESH. CKE is an SSTL_2
input but will detect an LVCMOS LOW level after VDD is applied and until
CKE is first brought HIGH, after which it becomes an SSTL_2 input only.
24 CS# Input Chip select: CS# enables (regis tered LOW) and disables (registered HIGH)
the command decoder. All commands are masked when CS# is registered
HIGH. CS# provides for external bank selection on systems with multiple
banks. CS# is considered part of the command code.
47
20
47
DM
LDM
UDM
Input Input data mask: DM is an input mask sig nal for write data. Input data is
masked when DM is sampled HIGH along with that input data during a write
access. DM is sampled on both edges of DQS. Although DM pins are input-
only, the DM loading is designed to match that of DQ and DQS pins. For the
x16, LDM is DM for DQ0–DQ7 and UDM is DM for DQ8–DQ15. Pin 20 is a NC
on x4 and x8.
23, 22, 21 RAS#, CAS#,
WE# Input Command inputs: RAS#, CAS#, and WE# (along with CS#) define the
command being entered.
2, 4, 5, 7,
8, 10, 11, 13,
54, 56, 57, 59,
60, 62, 63, 65
DQ0–DQ3
DQ4–DQ7
DQ8–DQ11
DQ12–DQ15
I/O Data input/output: Data bu s for x16.
2, 5, 8, 11,
56, 59, 62, 65 DQ0–DQ3
DQ4–DQ7 I/O Data input/output: Data bus for x8.
5, 11, 56, 62 DQ0–DQ3 I/O Data input/output: Data bus for x4.
51
16
51
DQS
LDQS
UDQS
I/O Data strobe: Output with read data, input with write data. DQS is edge-
aligned with read data, cent ered in write data. It is used to capture data. For
the x16, LDQS is DQS for DQ0–DQ7 and UDQS is DQS for DQ8–DQ15. Pin 16 is
NC on x4 and x8.
1, 18, 33 VDD Supply Power supply.
3, 9, 15, 55, 61 VDDQSupply DQ power supply: Isolated on the die for improved noise immunity.