AMS73CAG01808RA
Signal Pin Description
Pin
CK, CK
Type
Input
Function
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
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 V
REFCA
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.
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.
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.
The ODT pin will be ignored if the Mode Register (MR1) is pro-grammed to disable ODT.
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
HIGH coinci-dent with that input data during a Write access. DM is sampled on both edges of DQS.
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.
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.
Burst Chop:
A12 is sampled during Read and Write commands to determine if burst chop(on-the-fly)
will be per-formed. (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.
Data Input/ Output:
Bi-directional data bus.
Data Strobe:
Output with read data, input with write data. Edge-aligned with read data, centered in
write data. The data strobe DQS is paired with differential signal DQS to provide differential pair sig-
naling to the system during reads and writes. DDR3 SDRAM supports differential data strobe only and
does not support single-ended.
CKE
Input
CS
ODT
Input
Input
RAS, CAS, WE
DM
BA0 - BA2
Input
Input
Input
A0 - A13
Input
A10 / AP
Input
A12 / BC
RESET
Input
Input
DQ0 - DQ7
DQS, DQS
Input/
Output
Input/
Output
AMS73CAG01808RA
Rev. 1.0 December 2010
4
AMS [ Advanced Monolithic Systems Ltd ]
