IBMN312164CT3
IBMN312404CT3
IBMN312804CT3
128Mb Synchronous DRAM - Die Revision B
Preliminary
Current State Truth Table (Part 2 of 3)(See note 1)
Command
Current State
Action
Notes
CS RAS CAS WE BS0,BS1
A11 - A0
Description
L
L
L
L
L
L
L
H
L
L
L
L
L
L
L
H
L
L
L
L
L
L
L
H
L
L
L
L
L
L
L
H
L
L
L
L
L
H
L
OP Code
Mode Register Set
ILLEGAL
X
BS
BS
BS
BS
X
X
X
Auto or Self Refresh ILLEGAL
L
H
H
L
Precharge
ILLEGAL
ILLEGAL
ILLEGAL
ILLEGAL
4
4
4
4
Read with
Auto Pre-
charge
L
H
L
Row Address Bank Activate
H
H
H
X
L
Column
Write
L
H
H
X
L
Column
Read
H
X
L
X
X
No Operation
Device Deselect
Mode Register Set
Continue the Burst
Continue the Burst
ILLEGAL
X
OP Code
L
L
H
L
X
BS
BS
BS
BS
X
X
X
Auto or Self Refresh ILLEGAL
L
H
H
L
Precharge
ILLEGAL
4
4
4
4
Write with
Auto Pre-
charge
L
H
L
Row Address Bank Activate
ILLEGAL
H
H
H
X
L
Column
Write
ILLEGAL
L
H
H
X
L
Column
Read
ILLEGAL
H
X
L
X
X
No Operation
Device Deselect
Mode Register Set
Continue the Burst
Continue the Burst
ILLEGAL
X
OP Code
L
L
H
L
X
BS
BS
BS
BS
X
X
X
Auto or Self Refresh ILLEGAL
Precharge No Operation; Bank(s) idle after tRP
L
H
H
L
L
H
L
Row Address Bank Activate
ILLEGAL
ILLEGAL
ILLEGAL
4
4
4
Precharging
H
H
H
X
L
Column
Write
L
H
H
X
L
Column
Read
H
X
L
X
X
No Operation
Device Deselect
Mode Register Set
No Operation; Bank(s) idle after tRP
No Operation; Bank(s) idle after tRP
ILLEGAL
X
OP Code
L
L
H
L
X
BS
BS
BS
BS
X
X
X
Auto or Self Refresh ILLEGAL
L
H
H
L
Precharge
ILLEGAL
4
4, 10
4
L
H
L
Row Address Bank Activate
ILLEGAL
Row
Activating
H
H
H
X
Column
Write
ILLEGAL
L
H
H
X
Column
Read
ILLEGAL
4
H
X
X
X
No Operation
Device Deselect
No Operation; Row Active after tRCD
No Operation; Row Active after tRCD
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. All 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 to only 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) then 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. All rights reserved.
06K7582.H03335A
01/01
Use is further subject to the provisions at the end of this document.
Page 32 of 66
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