EDD51323DBH-LS
Command Operation
Command Truth Table
The DDR Mobile RAM recognizes the following commands specified by the /CS, /RAS, /CAS, /WE and address pins.
CKE
Command
Symbol
DESL
NOP
n − 1
H
n
/CS /RAS /CAS /WE BA1 BA0 AP
Address
Ignore command
H
H
H
H
H
H
H
H
H
H
H
L
H
L
L
L
L
L
L
L
L
L
L
L
L
L
×
H
H
H
H
H
H
L
×
H
H
L
×
H
L
×
×
×
V
V
V
V
V
V
×
×
×
L
×
×
×
V
V
V
V
V
V
×
×
×
L
L
×
×
×
L
H
L
H
V
L
H
×
×
L
L
×
×
×
V
V
V
V
V
×
×
×
×
V
V
No operation
H
Burst stop command
Column address and read command
Read with auto precharge
Column address and write command
Write with auto precharge
Row address strobe and bank active
Precharge select bank
Precharge all bank
BST
H
READ
READA
WRIT
WRITA
ACT
H
H
H
L
H
L
H
L
H
L
L
H
H
H
H
L
H
L
PRE
H
L
PALL
REF
H
L
L
Refresh
H
L
H
H
L
SELF
MRS
H
L
L
Mode register set
H
H
H
L
L
EMRS
H
L
L
L
H
Remark: H: VIH. L: VIL. ×: Don’t care V: Valid address input
Note: The CKE level must be kept for 1 CK cycle at least.
Ignore command [DESL]
When /CS is high at the cross point of the CK rising edge and the VDDQ/2 level, all input signals are neglected and
internal state is held.
No operation [NOP]
As long as this command is input at the cross point of the CK rising edge and the VDDQ/2 level, address and data
input are neglected and internal state is held.
Burst stop command [BST]
This command stops a current burst operation.
Column address strobe and read command [READ]
This command starts a read operation. The start address of the burst read is determined by the column address
(See “Address Pins Table” in Pin Function) and the bank select address. After the completion of the read operation,
all output buffers become high-Z.
Read with auto precharge [READA]
This command starts a read operation. After completion of the read operation, precharge is automatically executed.
Column address strobe and write command [WRIT]
This command starts a write operation. The start address of the burst write is determined by the column address
(See “Address Pins Table” in Pin Function) and the bank select address.
Write with auto precharge [WRITA]
This command starts a write operation. After completion of the write operation, precharge is automatically executed.
Preliminary Data Sheet E1432E20 (Ver. 2.0)
15
ELPIDA [ ELPIDA MEMORY ]
