Cypress CY7C1338G User Manual
Page 6
CY7C1338G
Document #: 38-05521 Rev. *D
Page 6 of 17
Truth Table
[2, 3, 4, 5, 6]
Cycle Description
Address
Used
CE
1
CE
2
CE
3
ZZ ADSP ADSC
ADV
WRITE OE CLK
DQ
Deselected Cycle, Power-down
None
H
X
X
L
X
L
X
X
X
L-H Tri-State
Deselected Cycle, Power-down
None
L
L
X
L
L
X
X
X
X
L-H Tri-State
Deselected Cycle, Power-down
None
L
X
H
L
L
X
X
X
X
L-H Tri-State
Deselected Cycle, Power-down
None
L
L
X
L
H
L
X
X
X
L-H Tri-State
Deselected Cycle, Power-down
None
X
X
X
L
H
L
X
X
X
L-H Tri-State
Sleep 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. The SRAM always initiates a read cycle when ADSP is asserted, regardless of the state of GW, BWE, or BW
X
. 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.
6. 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).