Rev. 1.1 / Apr. 2013 7
Pin Functional Description
Symbol 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.
CKE, (CKE0),
(CKE1) 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 operation (all banks idle), or Active Power-Down (row Active in any
bank).
CKE is asynchronous for Self-Refr esh exit. Af ter VREFCA and VREFDQ have become stable
during the power on and initialization sequence, they must be maintained during all
operations (including Self-Refresh). CKE must be maintained high throughout read and
write accesses. Input buff ers, excluding CK, CK, ODT and CKE, are disabled during power -
down. Input buffers, excluding CKE, are disabled during Self-Refresh.
CS, (CS0),
(CS1), (CS2),
(CS3) 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, (ODT0),
(ODT1) Input
On Die Termination: ODT (register ed HI GH) enables termination re sistance 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 x4/x8
configurations
RAS.
CAS. WE Input Command Inputs: RAS, CAS and WE (along with CS) define the command being entered.
DM, (DMU),
(DML) Input
Input Data Mask: DM is an input mask signal for write data. Input data is masked when
DM is sampled HIGH coincident with that input data during a Write acce ss. DM is sampled
on both edges of DQS. For x8 device, the function of DM or TDQS/TDQS is enabled by
Mode Register A11 setting in MR1.
BA0 - BA2 Input Bank Address Inputs: BA0 - BA2 define to which bank an Active, Read, W rite or Precharge
command is being applied. Bank address also determine s if the mode register or extended
mode register is to be accessed during a MRS cycle.
A0 - A15 Input
Address Inputs: Pro vide the row address f or Active comma nds and the column address f or
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
Auto-precharge: A10 is sampled during Read/Write commands to determine whether
Autoprecharge should be perform ed to the accessed bank after the R ead/W rite oper ation.
(HIGH: Autoprecharge; LOW: no Autoprecharge).A10 is sampled during a Precharge
command to determine whether the Precharge 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 Input Burst Chop: A12 / BC 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.