CY7C1470BV25
CY7C1472BV25, CY7C1474BV25
Document #: 001-15032 Rev. *D
Page 10 of 29
Table 4. Truth Table
The truth table for CY7C1470BV25, CY7C1472BV25, and CY7C1474BV25 follows. [1, 2, 3, 4, 5, 6, 7]
Operation
Address
Used
CE
ZZ
ADV/LD
WE
BWx
OE
CEN
CLK
DQ
Deselect Cycle
None
H
L
L
X
X
X
L
L-H
Tri-State
Continue Deselect Cycle
None
X
L
H
X
X
X
L
L-H
Tri-State
Read Cycle
(Begin Burst)
External
L
L
L
H
X
L
L
L-H
Data Out (Q)
Read Cycle
(Continue Burst)
Next
X
L
H
X
X
L
L
L-H
Data Out (Q)
NOP/Dummy Read
(Begin Burst)
External
L
L
L
H
X
H
L
L-H
Tri-State
Dummy Read
(Continue Burst)
Next
X
L
H
X
X
H
L
L-H
Tri-State
Write Cycle
(Begin Burst)
External
L
L
L
L
L
X
L
L-H
Data In (D)
Write Cycle
(Continue Burst)
Next
X
L
H
X
L
X
L
L-H
Data In (D)
NOP/Write Abort
(Begin Burst)
None
L
L
L
L
H
X
L
L-H
Tri-State
Write Abort
(Continue Burst)
Next
X
L
H
X
H
X
L
L-H
Tri-State
Ignore Clock Edge (Stall)
Current
X
L
X
X
X
X
H
L-H
–
Sleep Mode
None
X
H
X
X
X
X
X
X
Tri-State
Notes
1. X = “Don't Care”, H = Logic HIGH, L = Logic LOW, CE stands for ALL Chip Enables active. BWx = L signifies at least one Byte Write Select is active, BWx = Valid
signifies that the desired Byte Write Selects are asserted, see “Partial Write Cycle Description” on page 11 for details.
2. Write is defined by WE and BW[a:d]. See “Partial Write Cycle Description” on page 11 for details.
3. When a write cycle is detected, all IOs are tri-stated, even during Byte Writes.
4. The DQ and DQP pins are controlled by the current cycle and the OE signal.
5. CEN = H inserts wait states.
6. Device powers up deselected with the IOs in a tri-state condition, regardless of OE.
7. 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[a:d] = tri-state when OE is
inactive or when the device is deselected, and DQs = data when OE is active.
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