Ball Description
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
Pre-charge Power-Down and Self Refresh operation (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/L SDRAM. When enabled, ODT is only applied to each
DQ, DQS, /DQS and DM. The ODT pin will be ignored if the Mode Register
(MR1) is programmed 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 coincident with that input data during a
Write access. DM is sampled on both edges of DQS.
Bank Address Inputs: BA0-BA2 define the bank to which an Active, Read,
Write or Pre-charge command is being applied. Bank address also determines if
the mode register or extended mode register is to be accessed during a MRS
cycle.
Address Inputs: Provide 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. The address inputs also provide the op-code during
Mode Register Set commands. (A10/AP and A12/BC have additional functions,
see below)
Auto Pre-charge: A10 is sampled during Read/Write commands to determine
whether Auto pre-charge should be performed to the accessed bank after the
Read/Write operation (HIGH: Auto pre-charge; LOW: No Auto pre-charge). A10
is sampled during a Pre-charge 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 pre-charged, 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 performed. (HIGH: no burst chop, LOW: burst
chopped). See command truth table for details.