AS7C33256NTD32A
AS7C33256NTD36A
®
Burst Order
Interleaved Burst Order (LBO=1)
A1 A0 A1 A0 A1 A0 A1 A0
Linear Burst Order (LBO=0)
A1 A0 A1 A0 A1 A0 A1 A0
Starting Address 0 0
0 1
0 0
1 1
1 0
1 0
1 1
0 0
0 1
1 1
1 0
0 1
0 0
Starting Address 0 0
First increment 0 1
Second increment 1 0
Third increment 1 1
0 1
1 0
1 1
0 0
1 0
1 1
0 0
0 1
1 1
0 0
0 1
1 0
First increment 0 1
Second increment 1 0
Third increment 1 1
[5,6,7,8,9
]
Synchronous truth table
Address
OE CEN source
CE0 CE1 CE2 ADV/LD R/W
BWn
X
CLK
Operation
DQ
High-Z
High-Z
High-Z
High-Z
Q
Notes
H
X
X
X
L
X
X
L
X
H
X
X
L
L
L
L
H
L
H
L
H
L
H
L
X
X
X
X
H
X
H
X
L
X
X
X
X
L
L
L
L
L
L
L
L
L
L
L
L
NA
NA
NA
NA
L to H
L to H
L to H
L to H
DESELECT Cycle
DESELECT Cycle
X
X
DESELECT Cycle
X
H
X
H
X
H
X
H
X
CONTINUE DESELECT Cycle
READ Cycle (Begin Burst)
READ Cycle (Continue Burst)
1
X
External L to H
Next L to H
X
L
X
L
X
L
Q
1,10
2
X
H
H
X
X
X
External L to H NOP/DUMMY READ (Begin Burst) High-Z
X
L
X
L
X
Next L to H DUMMY READ (Continue Burst) High-Z 1,2,10
L
External L to H
WRITE CYCLE (Begin Burst)
D
D
3
X
L
X
L
X
L
L
Next L to H WRITE CYCLE (Continue Burst)
1,3,10
H
External L to H NOP/WRITE ABORT (Begin Burst) High-Z 2,3
1,2,3,
X
X
X
H
X
H
X
X
L
Next L to H WRITE ABORT (Continue Burst)
High-Z
10
X
X
X
X
X
X
H
Current L to H
INHIBIT CLOCK
-
4
Key: X = Don’t Care, H = HIGH, L = LOW. BWn = H means all byte write signals (BWa, BWb, BWc, and BWd) are HIGH. BWn = L means one or
more byte write signals are LOW.
Notes:
1 CONTINUE BURST cycles, whether READ or WRITE, use the same control inputs. The type of cycle performed (READ or WRITE) is chose in the initial
BEGIN BURST cycle. A CONINUE DESELECT cycle can only be entered if a DESELECT CYCLE is executed first.
2 DUMMY READ and WRITE ABORT cycles can be considered NOPs because the device performs no external operation. A WRITE ABORT means a
WRITE command is given, but no operation is performed.
3 OE may be wired LOW to minimize the number of control signal to the SRAM. The device will automatically turn off the output drivers during a WRITE
cycle. OE may be used when the bus turn-on and turn-off times do not meet an application’s requirements.
4 If an INHIBIT CLOCK command occurs during a READ operation, the DQ bus will remain active (Low-Z). If it occurs during a WRITE cycle, the bus
will remain in High-Z. No WRITE operations will be performed during the INHIBIT CLOCK cycle.
5 BWa enables WRITEs to byte “a” (DQa pins/balls); BWb enables WRITEs to byte “b” (DQb pins/balls); BWc enables WRITEs to byte “c” (DQc pins/
balls); BWd enables WRITEs to byte “d” (DQd pins/balls).
6 All inputs except OE and ZZ must meet setup and hold times around the rising edge (LOW to HIGH) of CLK.
7 Wait states are inserted by setting CEN HIGH.
8 This device contains circuitry that will ensure that the outputs will be in High-Z during power-up.
9 The device incorporates a 2-bit burst counter. Address wraps to the initial address every fourth BURST CYCLE.
10 The address counter is incremented for all CONTINUE BURST cycles.
11 ZZ pin is always Low in this truth table.
11/30/04, v. 2.1
Alliance Semiconductor
P. 6 of 19
ISSI [ INTEGRATED SILICON SOLUTION, INC ]
