CY7C1471V25
CY7C1473V25
CY7C1475V25
Document #: 38-05287 Rev. *I
Page 11 of 32
Truth Table
The truth table for CY7C1471V25, CY7C1473V25, and CY7C1475V25 follows.[2, 3, 4, 5, 6, 7, 8]
Operation
Address
Used
CE1 CE2 CE3 ZZ ADV/LD
WE
BWX
OE
CEN CLK
DQ
Deselect Cycle
None
H
X
X
L
L
X
X
X
L
L->H
Tri-State
Deselect Cycle
None
X
X
H
L
L
X
X
X
L
L->H
Tri-State
Deselect Cycle
None
X
L
X
L
L
X
X
X
L
L->H
Tri-State
Continue Deselect Cycle
None
X
X
X
L
H
X
X
X
L
L->H
Tri-State
Read Cycle
(Begin Burst)
External
L
H
L
L
L
H
X
L
L
L->H Data Out (Q)
Read Cycle
(Continue Burst)
Next
X
X
X
L
H
X
X
L
L
L->H Data Out (Q)
NOP/Dummy Read
(Begin Burst)
External
L
H
L
L
L
H
X
H
L
L->H
Tri-State
Dummy Read
(Continue Burst)
Next
X
X
X
L
H
X
X
H
L
L->H
Tri-State
Write Cycle
(Begin Burst)
External
L
H
L
L
L
L
L
X
L
L->H Data In (D)
Write Cycle
(Continue Burst)
Next
X
X
X
L
H
X
L
X
L
L->H Data In (D)
NOP/Write Abort
(Begin Burst)
None
L
H
L
L
L
L
H
X
L
L->H
Tri-State
Write Abort
(Continue Burst)
Next
X
X
X
L
H
X
H
X
L
L->H
Tri-State
Ignore Clock Edge (Stall)
Current
X
X
X
L
X
X
X
X
H
L->H
-
Sleep Mode
None
X
X
X
H
X
X
X
X
X
X
Tri-State
Notes
2. X = “Don't Care.” H = Logic HIGH, L = Logic LOW. BWX = L signifies at least one Byte Write Select is active, BWX = Valid signifies that the desired Byte Write
Selects are asserted, see “Truth Table for Read/Write” on page 12 for details.
3. Write is defined by BWX, and WE. See “Truth Table for Read/Write” on page 12.
4. When a write cycle is detected, all IOs are tri-stated, even during byte writes.
5. The DQs and DQPX pins are controlled by the current cycle and the OE signal. OE is asynchronous and is not sampled with the clock.
6. CEN = H, inserts wait states.
7. Device powers up deselected with the IOs in a tri-state condition, regardless of OE.
8. OE is asynchronous and is not sampled with the clock rise. It is masked internally during write cycles. During a read cycle DQs and DQPX = tri-state when OE
is inactive or when the device is deselected, and DQs and DQPX = data when OE is active.