IBM0316809C IBM0316409C
IBM0316169C
16Mbit Synchronous DRAM
Current State Truth Table (Notes: 1)
Command
Current State
Action
Notes
CS RAS CAS WE A11
A10 - A0
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
OP Code
Mode Register Set
Set the Mode Register
2
X
X
X
X
Auto or Self Refresh Start Auto or Self Refresh
2, 3
L
H
H
L
Precharge
No Operation
L
H
L
BS Row Address Bank Activate
Activate the specified bank and row
H
H
H
H
X
L
Column
Write w/o Precharge ILLEGAL
Read w/o Precharge ILLEGAL
4
4
Idle
Row Active
Read
BS
BS
X
L
H
L
Column
H
H
X
L
X
X
X
Burst Termination
No Operation
No Operation
H
X
L
X
No Operation
X
Device Deselect
Mode Register Set
No Operation or Power Down
ILLEGAL
5
OP Code
L
L
H
L
X
X
X
X
Auto or Self Refresh ILLEGAL
L
H
H
L
Precharge
Precharge
6
L
H
L
BS Row Address Bank Activate
ILLEGAL
4
H
H
H
H
X
L
Column
Write
Start Write; Determine if Auto Precharge
Start Read; Determine if Auto Precharge
No Operation
7, 8
7, 8
BS
BS
X
L
H
L
Column
Read
H
H
X
L
X
X
X
Burst Termination
No Operation
Device Deselect
Mode Register Set
H
X
L
X
No Operation
X
No Operation
OP Code
ILLEGAL
L
L
H
L
X
X
X
X
Auto or Self Refresh ILLEGAL
Precharge Terminate Burst; Start the Precharge
L
H
H
L
L
H
L
BS Row Address Bank Activate
ILLEGAL
4
H
H
H
H
X
Column
Write
Terminate Burst; Start the Write cycle
Terminate Burst; Start a new Read cycle
Terminate the Burst
8, 9
8, 9
BS
BS
X
L
H
L
Column
Read
H
H
X
X
X
X
Burst Termination
No Operation
Device Deselect
H
X
X
Continue the Burst
X
Continue the Burst
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 26 of 100
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