CY7C1370DV25
CY7C1372DV25
Document #: 38-05558 Rev. *D
Page 9 of 27
Truth Table[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
Partial Write Cycle Description[1, 2, 3, 8]
Function (CY7C1370DV25)
WE
BWd
BWc
BWb
BWa
Read
H
X
X
X
X
Write – No bytes written
L
H
H
H
H
Write Byte a – (DQa and DQPa)
L
HHH
L
Write Byte b – (DQb and DQPb)L
H
H
L
H
Write Bytes b, a
L
H
H
L
L
Write Byte c – (DQc and DQPc)L
H
L
H
H
Write Bytes c, a
L
H
L
H
L
Write Bytes c, b
L
H
L
L
H
Write Bytes c, b, a
L
H
L
L
L
Write Byte d – (DQd and DQPd)L
L
H
H
H
Write Bytes d, a
L
L
H
H
L
Write Bytes d, b
L
LHLH
Write Bytes d, b, a
L
L
H
L
L
Write Bytes d, c
L
L
L
H
H
Write Bytes d, c, a
L
L
L
H
L
Write Bytes d, c, b
L
L
L
L
H
Write All Bytes
L
L
L
L
L
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 Write Cycle Description table for details.
2. Write is defined by WE and BWX. See Write Cycle Description table for details.
3. When a write cycle is detected, all I/Os 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 will power-up deselected and the I/Os 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 DQPX = Three-state when
OE is inactive or when the device is deselected, and DQs = data when OE is active.
8. Table only lists a partial listing of the byte write combinations. Any Combination of BWX is valid. Appropriate write will be done based on which byte write is active.
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