Cypress CY7C1381DV25 User Manual
Page 9
CY7C1381DV25, CY7C1381FV25
CY7C1383DV25, CY7C1383FV25
Document #: 38-05547 Rev. *E
Page 9 of 28
Truth Table
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
4. X = Don't Care, H = Logic HIGH, L = Logic LOW.
5. WRITE = L when any one or more byte write enable signals, and BWE = L or GW = L. WRITE = H when all byte write enable signals, BWE, GW = H.
6. The DQ pins are controlled by the current cycle and the OE signal. OE is asynchronous and is not sampled with the clock.
7. 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.
8. 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).