AS4C128M16D3LB-12BCN
Signal Pin Description
Pin
Type
Function
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 (read) data is referenced to
the crossings of CK and CK
CKE
Input
Clock Enable : CKE HIGH activates, and CKE Low deactivates, internal clock signals and device input
buffers and output drivers. Taking CKE Low provides Precharge Power-Down and Self Refresh oper-
ation (all banks idle), or Active Power-Down (Row Active in any bank). CKE is asynchronous for self
refresh exit. After VREFCA has become stable during the power on and initialization sequence, it must
be maintained during all operations (including Self-Refresh). CKE must be maintained high throughout
read and write accesses. Input buffers, excluding CK, CK, ODT and CKE are disabled during power-
down. Input buffers, excluding CKE, are disabled during Self -Refresh.
CS
Input
Input
Chip Select : All commands are masked when CS is registered HIGH. CS provides for external Rank
selection on systems with multiple Ranks. CS is considered part of the command code.
ODT
On Die Termination : ODT (registered HIGH) enables termination resistance internal to the DDR3
SDRAM. When enabled, ODT is only applied to each DQ, DQS, DQS and DM/TDQS, NU/TDQS
(When TDQS is enabled via Mode Register A11=1 in MR1) signal for x8 configurations. The ODT pin
will be ignored if the Mode Register (MR1) is programmed to disable ODT.
RAS, CAS, WE
Input
Input
Command Inputs : RAS, CAS and WE (along with CS) define the command being entered.
Input Data Mask : DM is an input mask signal for write data. Input data is masked when DM is sampled
DM
HIGH coincident with that input data during a Write access. DM is sampled on both edges of DQS.
(DMU), (DML)
BA0 - BA2
A0 - A14
Input
Input
Bank Address Inputs : BA0 - BA2 define to which bank an Active, Read, Write or Precharge command
is being applied. Bank address also determines which mode register is to be accessed during a MRS
cycle.
Address Inputs : Provided the row address for Active commands and the column address for Read /
Write commands to select one location out of the memory array in the respective bank. (A10/AP and
A12/BC have additional functions, see below)
The address inputs also provide the op-code during Mode Register Set commands.
A10 / AP
Input
Autoprecharge : A10 is sampled during Read/Write commands to determine whether Autoprecharge
should be per-formed to the accessed bank after the Read/Write operation. (HIGH:Autoprecharge;
LOW: No Autoprecharge)A10 is sampled during a Precharge command to determine whether the Pre-
charge applies to one bank (A10 LOW) or all banks (A10 HIGH). if only one bank is to be precharged,
the bank is selected by bank addresses.
A12 / BC
RESET
Input
Input
Burst Chop : A12 is sampled during Read and Write commands to determine if burst chop(on-the-fly)
will be performed. (HIGH : no burst chop, LOW : burst chopped). See command truth table for details.
Active Low Asynchronous Reset : Reset is active when RESET is LOW, and inactive when RESET
is HIGH. RESET must be HIGH during normal operation. RESET is a CMOS rail to rail signal with DC
high and low at 80% and 20% of VDD, i.e. 1.20V for DC high and 0.30V for DC low.
DQ
Input/
Data Input/ Output : Bi-directional data bus.
Output
DQS, DQS
Input/
Data Strobe : Output with read data, input with write data. Edge-aligned with read data, centered in
write data. For the x16, DQSL corresponds to the data on DQL0-DQL7; DQSU corresponds to the data
on DQU0-DQU7. The data strobe DQS, DQSL and DQSU are paired with differential signals DQS,
DQSL and DQSU, respectively, to provide differential pair signaling to the system during reads and
writes. DDR3 SDRAM supports differential data strobe only and does not support single-ended.
Output
Confidential
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Rev.1.0 Mar 2016
ALSC [ ALLIANCE SEMICONDUCTOR CORPORATION ]
