HYB25D256[400/800/160]B[T/C](L)
256-Mbit Double Data Rate SDRAM
Functional Description
Table 10
Truth Table 4: Current State Bank n - Command to Bank m (different bank)
Current State
CS RAS CAS WE Command
Action
Notes
1) to 6)2)3)4)5)6)
Any
H
X
H
X
X
H
X
X
H
X
Deselect
NOP. Continue previous
operation.
1) to 6)
1) to 6)
L
No Operation
NOP. Continue previous
operation.
Idle
X
Any Command
Otherwise Allowed
to Bank m
–
1) to 6)
1) to 7)
Row Activating,
Active, or
Precharging
L
L
L
H
L
H
H
Active
Read
Select and activate row
H
Select column and start
Read burst
1) to 7)
L
H
L
L
Write
Select column and start Write
burst
1) to 6)
1) to 6)
1) to 7)
L
L
L
L
L
H
H
H
L
L
Precharge
Active
–
Read (Auto
Precharge
Disabled)
H
H
Select and activate row
Read
Select column and start new
Read burst
1) to 6)
1) to 6)
1) to 8)
L
L
L
L
L
H
H
H
L
L
Precharge
Active
–
Write (Auto
Precharge
Disabled)
H
H
Select and activate row
Read
Select column and start Read
burst
1) to 7)
L
H
L
L
Write
Select column and start new
Write burst
1) to 6)
L
L
L
H
H
H
L
L
Precharge
Active
–
1) to 6)
Read (With Auto L
H
H
Select and activate row
1) to 7), 10)9)
Precharge)
L
Read
Select column and start new
Read burst
1) to 7), 9), 10)
L
H
L
L
Write
Select column and start Write
burst
1) to 6)
L
L
L
H
H
H
L
L
Precharge
Active
–
1) to 6)
Write (With Auto L
H
H
Select and activate row
1) to 7), 9)
Precharge)
L
Read
Select column and start Read
burst
1) to 7), 9)
1) to 6)
L
L
H
L
L
L
L
Write
Select column and start new
Write burst
H
Precharge
–
1) This table applies when CKE n-1 was HIGH and CKE n is HIGH (see Table 8: Clock Enable (CKE) and after tXSNR/tXSRD
has been met (if the previous state was self refresh).
2) This table describes alternate bank operation, except where noted, i.e., the current state is for bank n and the commands
shown are those allowed to be issued to bank m (assuming that bank m is in such a state that the given command is
allowable). Exceptions are covered in the notes below.
Data Sheet
51
Rev. 1.21, 2004-07
02102004-TSR1-4ZWW
QIMONDA [ QIMONDA AG ]
