Truth table – Cypress CY7C1339G User Manual
Page 6
CY7C1339G
Document #: 38-05520 Rev. *F
Page 6 of 18
Truth Table
[2, 3, 4, 5, 6, 7]
Operation
Add. Used
CE
1
CE
2
CE
3
ZZ
ADSP
ADSC
ADV
WRITE
OE CLK
DQ
Deselect Cycle, Power-down
None
H
X
X
L
X
L
X
X
X
L-H
Tri-State
Deselect Cycle, Power-down
None
L
L
X
L
L
X
X
X
X
L-H
Tri-State
Deselect Cycle, Power-down
None
L
X
H
L
L
X
X
X
X
L-H
Tri-State
Deselect Cycle, Power-down
None
L
L
X
L
H
L
X
X
X
L-H
Tri-State
Deselect Cycle, Power-down
None
L
X
H
L
H
L
X
X
X
L-H
Tri-State
Snooze Mode, Power-down
None
X
X
X
H
X
X
X
X
X
X
Tri-State
READ Cycle, Begin Burst
External
L
H
L
L
L
X
X
X
L
L-H
Q
READ Cycle, Begin Burst
External
L
H
L
L
L
X
X
X
H
L-H
Tri-State
WRITE Cycle, Begin Burst
External
L
H
L
L
H
L
X
L
X
L-H
D
READ Cycle, Begin Burst
External
L
H
L
L
H
L
X
H
L
L-H
Q
READ Cycle, Begin Burst
External
L
H
L
L
H
L
X
H
H
L-H
Tri-State
READ Cycle, Continue Burst
Next
X
X
X
L
H
H
L
H
L
L-H
Q
READ Cycle, Continue Burst
Next
X
X
X
L
H
H
L
H
H
L-H
Tri-State
READ Cycle, Continue Burst
Next
H
X
X
L
X
H
L
H
L
L-H
Q
READ Cycle, Continue Burst
Next
H
X
X
L
X
H
L
H
H
L-H
Tri-State
WRITE Cycle, Continue Burst
Next
X
X
X
L
H
H
L
L
X
L-H
D
WRITE Cycle, Continue Burst
Next
H
X
X
L
X
H
L
L
X
L-H
D
READ Cycle, Suspend Burst
Current
X
X
X
L
H
H
H
H
L
L-H
Q
READ Cycle, Suspend Burst
Current
X
X
X
L
H
H
H
H
H
L-H
Tri-State
READ Cycle, Suspend Burst
Current
H
X
X
L
X
H
H
H
L
L-H
Q
READ Cycle, Suspend Burst
Current
H
X
X
L
X
H
H
H
H
L-H
Tri-State
WRITE Cycle, Suspend Burst
Current
X
X
X
L
H
H
H
L
X
L-H
D
WRITE Cycle, Suspend Burst
Current
H
X
X
L
X
H
H
L
X
L-H
D
Notes:
2. X = “Don't Care.” H = Logic HIGH, L = Logic LOW.
3. WRITE = L when any one or more Byte Write enable signals (BW
A
, BW
B
, BW
C
, BW
D
) and BWE = L or GW= L. WRITE = H when all Byte write enable signals
(BW
A
, BW
B
, BW
C
, BW
D
), BWE, GW = H.
4. The DQ pins are controlled by the current cycle and the OE signal. OE is asynchronous and is not sampled with the clock.
5. CE
1
, CE
2
, and CE
3
are available only in the TQFP package. BGA package has only 2 chip selects CE
1
and CE
2
.
6. The SRAM always initiates a read cycle when ADSP is asserted, regardless of the state of GW, BWE, or BW
[A: D]
. Writes may occur only on subsequent clocks
after the ADSP or with the assertion of ADSC. As a result, OE must be driven HIGH prior to the start of the write cycle to allow the outputs to tri-state. OE is a
don't care for the remainder of the write cycle.
7. OE is asynchronous and is not sampled with the clock rise. It is masked internally during write cycles. During a read cycle all data bits are tri-state when OE is
inactive or when the device is deselected, and all data bits behave as output when OE is active (LOW).