
25
64Mb: x32 SDRAM, 2.5V
BatRam_25V.p65 – Rev. 0.7, Pub. 2/01
Micron Technology, Inc., reserves the right to change products or specifications without notice.
2001, Micron Technology, Inc.
64Mb: x32, 2.5V
SDRAM
PRELIMINARY
TRUTH TABLE 2 – CKE
(Notes: 1–4)
CKE
n-1
CKE
n
L
CURRENT STATE
Power-Down
Self Refresh
Clock Suspend
Power-Down
Self Refresh
Clock Suspend
All Banks Idle
All Banks Idle
Reading or Writing
COMMA ND
n
X
X
X
COMMAND INHIBIT or NOP
COMMAND INHIBIT or NOP
X
COMMAND INHIBIT or NOP
AUTO REFRESH
VALID
See Truth Table 3
A CTION
n
Maintain Power-Down
Maintain Self Refresh
Maintain Clock Suspend
Exit Power-Down
Exit Self Refresh
Exit Clock Suspend
Power-Down Entry
Self Refresh Entry
Clock Suspend Entry
NOTES
L
L
H
5
6
7
H
L
H
H
NOTE:
1. CKE
is the logic state of CKE at clock edge
n
; CKE
was the state of CKE at the previous clock edge.
2. Current state is the state of the SDRAM immediately prior to clock edge
n
.
3. COMMAND
n
is the command registered at clock edge
n
, and ACTION
n
is a result of COMMAND
n
.
4. All states and sequences not shown are illegal or reserved.
5. Exiting power-down at clock edge
n
will put the device in the all banks idle state in time for clock edge
n + 1
(provided
that
t
CKS is met).
6. Exiting self refresh at clock edge
n
will put the device in the all banks idle state once
t
XSR is met. COMMAND INHIBIT
or NOP commands should be issued on any clock edges occurring during the
t
XSR period. A minimum of two NOP
commands must be provided during
t
XSR period.
7. After exiting clock suspend at clock edge
n
, the device will resume operation and recognize the next command at clock
edge
n + 1
.