Rev. 0.5 / Jun. 2004

5

HY5DW283222AF

PIN DESCRIPTION

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).

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 operation (all banks idle), or ACTIVE POWER DOWN (row

ACTIVE in any bank). CKE is synchronous for POWER DOWN entry and exit, and for SELF

REFRESH entry. CKE is asynchronous for SELF REFRESH exit, and for output disable. 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. CKE is an SSTL_2 input, but will detect an LVCMOS LOW

level after Vdd is applied.

/CS

Input

Chip Select : Enables or disables all inputs except CK, /CK, CKE, DQS and DM. All com-

mands are masked when CS is registered high. CS provides for external bank selection on

systems with multiple banks. CS is considered part of the command code.

BA0, BA1

Input

Bank Address Inputs: BA0 and BA1 define to which bank an ACTIVE, Read, Write or PRE-

CHARGE command is being applied.

A0 ~ A11

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. A8 is sampled during a precharge command to

determine whether the PRECHARGE applies to one bank (A8 LOW) or all banks (A8

HIGH). If only one bank is to be precharged, the bank is selected by BA0, BA1. The

address inputs also provide the op code during a MODE REGISTER SET command. BA0

and BA1 define which mode register is loaded during the MODE REGISTER SET command

(MRS or EMRS).

/RAS, /CAS, /WE

Input

Command Inputs: /RAS, /CAS and /WE (along with /CS) define the command being

entered.

DM0 ~ DM3

Input

Input Data Mask: DM(0~3) is an input mask signal for write data. Input data is masked

when DM is sampled HIGH along with that input data during a WRITE access. DM is sam-

pled on both edges of DQS. Although DM pins are input only, the DM loading matches the

DQ and DQS loading. DM0 corresponds to the data on DQ0-Q7; DM1 corresponds to the

data on DQ8-Q15; DM2 corresponds to the data on DQ16-Q23; DM3 corresponds to the

data on DQ24-Q31.

DQS0~DQS3

I/O

Data Strobe: Output with read data, input with write data. Edge aligned with read data,

centered in write data. Used to capture write data. DQS0 corresponds to the data on

DQ0-Q7; DQS1 corresponds to the data on DQ8-Q15; DQS2 corresponds to the data on

DQ16-Q23; DQS3 corresponds to the data on DQ24-Q31

DQ0 ~ DQ31

I/O

Data input / output pin : Data Bus

Supply

Power supply for internal circuits and input buffers.

Supply

Power supply for output buffers for noise immunity.

Supply

Reference voltage for inputs for SSTL interface.

NC

NC

No connection.