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
CE
1
CE
2
CE
3
ZZ ADV/LD
WE
BW
X
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. BW
X
= L signifies at least one Byte Write Select is active, BW
X
= 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 BW
X
, 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 DQP
X
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 DQP
X
= tri-state when OE
is inactive or when the device is deselected, and DQs and DQP
X
= data when OE is active.
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