IS42S16400D
TRUTH TABLE – CURRENT STATE BANK
n,
COMMAND TO BANK
m
(1-6)
CURRENT STATE
Any
Idle
Row
Activating,
Active, or
Precharging
Read
(Auto
Precharge
Disabled)
Write
(Auto
Precharge
Disabled)
Read
(With Auto
Precharge)
Write
(With Auto
Precharge)
COMMAND (ACTION)
COMMAND INHIBIT (NOP/Continue previous operation)
NO OPERATION (NOP/Continue previous operation)
Any Command Otherwise Allowed to Bank
m
ACTIVE (Select and activate row)
READ (Select column and start READ burst)
(7)
WRITE (Select column and start WRITE burst)
(7)
PRECHARGE
ACTIVE (Select and activate row)
READ (Select column and start new READ burst)
(7,10)
WRITE (Select column and start WRITE burst)
(7,11)
PRECHARGE
(9)
ACTIVE (Select and activate row)
READ (Select column and start READ burst)
(7,12)
WRITE (Select column and start new WRITE burst)
(7,13)
PRECHARGE
(9)
ACTIVE (Select and activate row)
READ (Select column and start new READ burst)
(7,8,14)
WRITE (Select column and start WRITE burst)
(7,8,15)
PRECHARGE
(9)
ACTIVE (Select and activate row)
READ (Select column and start READ burst)
(7,8,16)
WRITE (Select column and start new WRITE burst)
(7,8,17)
PRECHARGE
(9)
ISSI
H
L
X
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
X
H
X
L
H
H
L
L
H
H
L
L
H
H
L
L
H
H
L
L
H
H
L
X
H
X
H
L
L
H
H
L
L
H
H
L
L
H
H
L
L
H
H
L
L
H
X
H
X
H
H
L
L
H
H
L
L
H
H
L
L
H
H
L
L
H
H
L
L
®
CS RAS CAS WE
NOTE:
1. This table applies when CKE n-1 was HIGH and CKE n is HIGH (Truth Table - CKE) and after t
XSR
has been met (if the previous
state was self refresh).
2. This table describes alternate bank operation, except where noted; i.e., the current state is for bank
n
and the commands shown
are those allowed to be issued to bank
m
(assuming that bank
m
is in such a state that the given command is allowable). Exceptions are
covered in the notes below.
3. Current state definitions:
Idle: The bank has been precharged, and t
RP
has been met.
Row Active: A row in the bank has been activated, and t
RCD
has been met. No data bursts/accesses and no register
accesses are in progress.
Read: A READ burst has been initiated, with auto precharge disabled, and has not yet terminated or been terminated.
Write: A WRITE burst has been initiated, with auto precharge disabled, and has not yet terminated or been terminated.
Read w/Auto
Precharge Enabled: Starts with registration of a READ command with auto precharge enabled, and ends when t
RP
has been met.
Once t
RP
is met, the bank will be in the idle state.
Write w/Auto
Precharge Enabled: Starts with registration of a WRITE command with auto precharge enabled, and ends when t
RP
has been
met. Once t
RP
is met, the bank will be in the idle state.
4. AUTO REFRESH, SELF REFRESH and LOAD MODE REGISTER commands may only be issued when all banks are idle.
5. A BURST TERMINATE command cannot be issued to another bank; it applies to the bank represented by the current state only.
6. All states and sequences not shown are illegal or reserved.
10
Integrated Silicon Solution, Inc. — www.issi.com —
1-800-379-4774
Rev. C
07/05/06
ISSI [ INTEGRATED SILICON SOLUTION, INC ]
