IBM0316409C IBM0316809C
IBM0316169C
16Mbit Synchronous DRAM
Current State Truth Table (Continued) (Notes: 1)
Command
Current State
Action
Notes
CS RAS CAS WE A11
A10 - A0
OP Code
Description
L
L
L
L
L
L
L
L
H
L
L
L
L
L
L
L
L
H
L
L
L
L
L
L
L
L
H
L
L
L
L
L
H
L
Mode Register Set
ILLEGAL
X
X
X
X
Auto or Self Refresh ILLEGAL
L
H
H
L
Precharge
ILLEGAL
ILLEGAL
ILLEGAL
ILLEGAL
4
L
H
L
BS Row Address Bank Activate
4
Write
Recovering
with Auto
Precharge
H
H
H
H
X
L
Column
Write
4, 9
4, 9
BS
BS
X
L
H
L
Column
Read
No Operation; Precharge after tDPL
No Operation; Precharge after tDPL
No Operation; Precharge after tDPL
ILLEGAL
H
H
X
L
X
X
X
Burst Termination
No Operation
Device Deselect
Mode Register Set
H
X
L
X
X
OP Code
L
L
H
L
X
X
X
X
Auto or Self Refresh ILLEGAL
L
H
H
L
Precharge
ILLEGAL
L
H
L
BS Row Address Bank Activate
ILLEGAL
H
H
H
H
X
L
Column
Write
ILLEGAL
BS
BS
X
Refreshing
L
H
L
Column
Read
ILLEGAL
No Operation; Idle after tRC
No Operation; Idle after tRC
No Operation; Idle after tRC
ILLEGAL
H
H
X
L
X
X
X
Burst Termination
No Operation
Device Deselect
Mode Register Set
H
X
L
X
X
OP Code
L
L
H
L
X
X
X
X
Auto or Self Refresh ILLEGAL
L
H
H
L
Precharge
ILLEGAL
L
H
L
BS Row Address Bank Activate
ILLEGAL
Mode Register
Accessing
H
H
H
H
X
Column
Write
ILLEGAL
BS
BS
X
L
H
L
Column
Read
ILLEGAL
H
H
X
X
X
X
Burst Termination
No Operation
Device Deselect
ILLEGAL
No Operation; Idle after two clock cycles
No Operation; Idle after two clock cycles
H
X
X
X
1. CKE is assumed to be active (high) in the previous cycle for all entries. The Current State is the state of the bank that the Com-
mand is being applied to.
2. Both Banks must be idle otherwise it is an illegal action.
3. If CKE is active (high) the SDRAM will start the Auto (CBR) Refresh operation, if CKE is inactive (low) than the Self Refresh mode
is entered.
4. The Current State refers only refers to one of the banks, if BS selects this bank then the action is illegal. If BS selects the bank not
being referenced by the Current State then the action may be legal depending on the state of that bank.
5. If CKE is inactive (low) than the Power Down mode is entered, otherwise there is a No Operation.
6. The minimum and maximum Active time (tRAS) must be satisfied.
7. The RAS to CAS Delay (tRCD) must occur before the command is given.
8. Column address A10 is used to determine if the Auto Precharge function is activated.
9. The command must satisfy any bus contention, bus turn around, and/or write recovery requirements.
10. The command is illegal if the minimum bank to bank delay time (tRRD) is not satisfied.
©IBM Corporation, 1996. All rights reserved.
Use is further subject to the provisions at the end of this document.
07H3997
SA14-4711-02
Revised 05/96
Page 29 of 100
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