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CY7C1440AV25
CY7C1442AV25
CY7C1446AV25
Document #: 38-05350 Rev. *E
Page 11 of 32
Truth Table for Read/Write[4,8,9]
Function (CY7C1440AV25)
GW
BWE
BWD
BWC
BWB
BWA
Read
H
H
X
X
X
X
Read
H
L
H
H
H
H
Write Byte A – ( DQA and DQPA )
H
L
HHH
L
Write Byte B – ( DQB and DQPB )H
L
H
H
L
H
Write Bytes B, A
H
L
H
H
L
L
Write Byte C – ( DQC and DQPC )H
L
H
L
H
H
Write Bytes C, A
H
L
H
L
H
L
Write Bytes C, B
H
L
H
L
L
H
Write Bytes C, B, A
H
L
H
L
L
L
Write Byte D – ( DQD and DQPD )H
L
L
H
H
H
Write Bytes D, A
H
L
L
H
H
L
Write Bytes D, B
H
L
L
H
L
H
Write Bytes D, B, A
H
L
L
H
L
L
Write Bytes D, C
H
L
L
L
H
H
Write Bytes D, C, A
H
L
L
L
H
L
Write Bytes D, C, B
H
L
L
L
L
H
Write All Bytes
H
L
L
L
L
L
Write All Bytes
L
XXXX
X
Truth Table for Read/Write[4,8,9]
Function (CY7C1442AV25)
GW
BWE
BWB
BWA
Read
H
H
X
X
Read
H
L
H
H
Write Byte A – ( DQA and DQPA )H
L
H
L
Write Byte B – ( DQB and DQPB )H
L
L
H
Write Bytes B, A
H
L
L
L
Write All Bytes
H
L
L
L
Truth Table for Read/Write[4,8,9]
Function (CY7C1446AV25)
GW
BWE
BWx
Read
HH
X
Read
H
L
All BW = H
Write Byte x – (DQx and DQPx)H
L
L
Write All Bytes
H
L
All BW = L
Notes:
8. BWx represents any byte write signal. To enable any byte write BWx, a Logic LOW signal should be applied at clock rise.Any number of bye writes can be enabled
at the same time for any given write.
9. 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.