IS42S16800A1 Datasheet, PDF (31/63 Pages) Integrated Silicon Solution, Inc – 8Meg x16 128-MBIT SYNCHRONOUS DRAM

IS42S16800A1
ISSI ^®
Current State Truth Table (Part 2 of 3)(See note 1)
Current State
Read with
Auto Pre-
charge
Write with Auto
Precharge
Precharging
Row
Activating
Command
CS RAS CAS WE BA0,BA1 A11 - A0
Description
LLLL
OP Code
Mode Register Set
L L LH
X
X
Auto or Self Refresh
L LHL
BS
X
Precharge
L LHH
BS Row Address Bank Activate
LHL L
BS
Column Write
LHLH
BS
Column Read
L HHH
X
X
No Operation
HXXX
X
X
Device Deselect
LLLL
OP Code
Mode Register Set
L L LH
X
X
Auto or Self Refresh
L LHL
BS
X
Precharge
L LHH
BS Row Address Bank Activate
LHL L
BS
Column Write
LHLH
BS
Column Read
L HHH
X
X
No Operation
HXXX
X
X
Device Deselect
LLLL
OP Code
Mode Register Set
L L LH
X
X
Auto or Self Refresh
L LHL
BS
X
Precharge
L LHH
BS Row Address Bank Activate
LHL L
BS
Column Write
LHLH
BS
Column Read
L HHH
X
X
No Operation
HXXX
X
X
Device Deselect
LLLL
OP Code
Mode Register Set
L L LH
X
X
Auto or Self Refresh
L LHL
BS
X
Precharge
L LHH
BS Row Address Bank Activate
LHL L
BS
Column Write
LHLH
BS
Column Read
L HHH
X
X
No Operation
HXXX
X
X
Device Deselect
Action
ILLEGAL
ILLEGAL
ILLEGAL
ILLEGAL
ILLEGAL
ILLEGAL
Continue the Burst
Continue the Burst
ILLEGAL
ILLEGAL
ILLEGAL
ILLEGAL
ILLEGAL
ILLEGAL
Continue the Burst
Continue the Burst
ILLEGAL
ILLEGAL
No Operation; Bank(s) idle after t_RP
ILLEGAL
ILLEGAL
ILLEGAL
No Operation; Bank(s) idle after t_RP
No Operation; Bank(s) idle after t_RP
ILLEGAL
ILLEGAL
ILLEGAL
ILLEGAL
ILLEGAL
ILLEGAL
No Operation; Row Active after t_RCD
No Operation; Row Active after t_RCD
Notes
4
4
4
4
4
4
4
4
4
4
4
4
4, 10
4
4
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 Command 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 refer-
enced 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 (t_RAS) must be satisfied.
7. The RAS to CAS Delay (t_RCD) 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 (t_RRD) is not satisfied.
Integrated Silicon Solution, Inc. — www.issi.com — 1-800-379-4774
©
31
Rev. 00B
05/01/06
N