PRELIMINARY
Truth Table
[1, 2, 3, 4, 5, 6, 7]
Operation
Deselect Cycle
Continue Deselect Cycle
Read Cycle (Begin Burst)
Read Cycle (Continue Burst)
NOP/Dummy Read (Begin Burst)
Dummy Read (Continue Burst)
Write Cycle (Begin Burst)
Write Cycle (Continue Burst)
NOP/Write Abort (Begin Burst)
Write Abort (Continue Burst)
Ignore Clock Edge (Stall)
Sleep Mode
Address
Used
None
None
External
Next
External
Next
External
Next
None
Next
Current
None
CE
H
X
L
X
L
X
L
X
L
X
X
X
ZZ
L
L
L
L
L
L
L
L
L
L
L
H
ADV/LD
L
H
L
H
L
H
L
H
L
H
X
X
WE
X
X
H
X
H
X
L
X
L
X
X
X
BW
x
X
X
X
X
X
X
L
L
H
H
X
X
OE
X
X
L
L
H
H
X
X
X
X
X
X
L
L
L
L
L
L
L
L
L
L
H
X
CY7C1370DV25
CY7C1372DV25
CEN
CLK
L-H
L-H
L-H
L-H
L-H
L-H
L-H
L-H
L-H
L-H
L-H
X
DQ
Three-State
Three-State
Data Out (Q)
Data Out (Q)
Three-State
Three-State
Data In (D)
Data In (D)
Three-State
Three-State
–
Three-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, BW
x
= Valid
signifies that the desired byte write selects are asserted, see Write Cycle Description table for details.
2. Write is defined by WE and BW
X
. 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 DQ
s
and DQP
X
= Three-state when OE
is inactive or when the device is deselected, and DQ
s
= data when OE is active.
8. Table only lists a partial listing of the byte write combinations. Any Combination of BW
X
is valid. Appropriate write will be done based on which byte write is active.
Document #: 38-05558 Rev. *A
Page 9 of 30
CYPRESS [ CYPRESS SEMICONDUCTOR ]
