HY5PS12421CFP-E3 Datasheet, PDF (8/38 Pages) Hynix Semiconductor – 512Mb DDR2 SDRAM

1.3 PIN DESCRIPTION
1HY5PS12421C(L)FP
1HY5PS12821C(L)FP
1HY5PS121621C(L)FP
PIN
TYPE
DESCRIPTION
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 (both directions of crossing).
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 synchronous for POWER DOWN entry and exit, and for
CKE
Input
SELF REFRESH entry. CKE is asynchronous for SELF REFRESH exit. After V_REF has
become stable during the power on and initialization sequence, it must be maintained
for proper operation of the CKE receiver. For proper self-refresh entry and exit, V_REF
must be maintained to this input. CKE must 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.
Chip Select : All commands are masked when CS is registered HIGH. CS provides for
CS
Input external bank selection on systems with multiple banks. CS is considered part of the
command code.
On Die Termination Control : ODT(registered HIGH) enables on die termination resis-
tance internal to the DDR2 SDRAM. When enabled, ODT is only applied to DQ, DQS,
ODT
Input DQS, RDQS, RDQS, and DM signal for x4,x8 configurations. For x16 configuration ODT
is applied to each DQ, UDQS/UDQS.LDQS/LDQS, UDM and LDM signal. The ODT pin
will be ignored if the Extended Mode Register(EMRS(1)) is programmed to disable ODT.
RAS, CAS, WE
Input
Command Inputs: RAS, CAS and WE (along with CS) define the command being
entered.
DM
(LDM, UDM)
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 access. DM
is sampled on both edges of DQS, Although DM pins are input only, the DM loading
matches the DQ and DQS loading. For x8 device, the function of DM or RDQS/ RDQS is
enabled by EMRS command.
BA0 - BA2
Input
Bank Address Inputs: BA0 - BA2 define to which bank an ACTIVE, Read, Write or PRE-
CHARGE command is being applied(For 256Mb and 512Mb, BA2 is not applied). Bank
address also determines if the mode register or extended mode register is to be
accessed during a MRS or EMRS cycle.
A0 -A15
Input
Address Inputs: Provide the row address for ACTIVE commands, and the column
address and AUTO PRECHARGE bit for READ/WRITE commands to select one location
out of the memory array in the respective bank. 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 BA0-
BA2. The address inputs also provide the op code during MODE REGISTER SET com-
mands.
DQ
Input/
Output
Data input / output : Bi-directional data bus
Rev. 0.8 / Oct. 2007
8