HYB25D256400BT Datasheet, PDF (5/77 Pages) Infineon Technologies AG – 256-Mbit Double Data Rate SDRAM, Die Rev. B

HYB25D256[400/800/160]B[T/C](L)
256-Mbit Double Data Rate SDRAM, Die Rev. B
Input/Output Functional Description
Symbol
CK, CK
CKE
CS
RAS, CAS, WE
DM
BA0, BA1
A0 - A12
DQ
DQS
NC
V_DDQ
V_SSQ
V_DD
V_SS
V_REF
Type
Input
Input
Input
Input
Input
Input
Input
Input/Output
Input/Output
Supply
Supply
Supply
Supply
Supply
Function
Clock: CK and CK are differential clock inputs. All address and control input signals are sam-
pled 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 self refresh entry. CKE is asyn-
chronous for self refresh exit. 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 exter-
nal bank selection on systems with multiple banks. CS is considered part of the command
code. The standard pinout includes one CS pin.
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. Although DM pins are input only, the DM loading matches the DQ and
DQS loading.
Bank Address Inputs: BA0 and BA1 define to which bank an Active, Read, Write or Pre-
charge command is being applied. BA0 and BA1 also determines if the mode register or
extended mode register is to be accessed during a MRS or EMRS cycle.
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, BA1. The address inputs also provide
the op-code during a Mode Register Set command.
Data Input/Output: Data bus.
Data Strobe: Output with read data, input with write data. Edge-aligned with read data, cen-
tered in write data. Used to capture write data.
No Connect: No internal electrical connection is present.
DQ Power Supply: 2.5V ± 0.2V.
DQ Ground
Power Supply: 2.5V ± 0.2V.
Ground
SSTL_2 reference voltage: (V_DDQ / 2)
Page 5 of 77
2003-01-09, V1.1