PRELIMINARY
CY7C1561KV18, CY7C1576KV18
CY7C1563KV18, CY7C1565KV18
Document Number: 001-15878 Rev. *E
Page 10 of 28
Truth Table
The truth table for CY7C1561KV18, CY7C1576KV18, CY7C1563KV18, and CY7C1565KV18 follows. [3, 4, 5, 6, 7, 8]
Operation
K
RPS WPS
DQ
DQ
DQ
DQ
Write Cycle:
Load address on the rising
edge of K; input write data
on two consecutive K and
K rising edges.
L-H
H [9] L [10] D(A) at K(t + 1)
↑ D(A + 1) at K(t + 1)↑ D(A + 2) at K(t + 2)↑ D(A + 3) at K(t + 2)↑
Read Cycle:
(2.5 cycle Latency)
Load address on the rising
edge of K; wait two and
half cycles; read data on
two consecutive K and K
rising edges.
L-H
L [10]
X
Q(A) at K(t + 2)
↑ Q(A + 1) at K(t + 3)↑ Q(A + 2) at K(t + 3)↑ Q(A + 3) at K(t + 4)↑
NOP: No Operation
L-H
H
H
D = X
Q = High-Z
D = X
Q = High-Z
D = X
Q = High-Z
D = X
Q = High-Z
Standby: Clock Stopped
Stopped
X
X
Previous State
Previous State
Previous State
Previous State
Write Cycle Descriptions
The write cycle description table for CY7C1561KV18 and CY7C1563KV18 follows. [3, 11]
BWS0/
NWS0
BWS1/
NWS1
K
K
Comments
L
L
L–H
–
During the data portion of a write sequence
:
CY7C1561KV18
− both nibbles (D[7:0]) are written into the device.
CY7C1563KV18
− both bytes (D[17:0]) are written into the device.
L
L
–
L-H During the data portion of a write sequence
:
CY7C1561KV18
− both nibbles (D[7:0]) are written into the device.
CY7C1563KV18
− both bytes (D[17:0]) are written into the device.
L
H
L–H
–
During the data portion of a write sequence
:
CY7C1561KV18
− only the lower nibble (D[3:0]) is written into the device, D[7:4] remains unaltered.
CY7C1563KV18
− only the lower byte (D[8:0]) is written into the device, D[17:9] remains unaltered.
L
H
–
L–H During the data portion of a write sequence
:
CY7C1561KV18
− only the lower nibble (D[3:0]) is written into the device, D[7:4] remains unaltered.
CY7C1563KV18
− only the lower byte (D[8:0]) is written into the device, D[17:9] remains unaltered.
H
L
L–H
–
During the data portion of a write sequence
:
CY7C1561KV18
− only the upper nibble (D[7:4]) is written into the device, D[3:0] remains unaltered.
CY7C1563KV18
− only the upper byte (D[17:9]) is written into the device, D[8:0] remains unaltered.
H
L
–
L–H During the data portion of a write sequence
:
CY7C1561KV18
− only the upper nibble (D[7:4]) is written into the device, D[3:0] remains unaltered.
CY7C1563KV18
− only the upper byte (D[17:9]) is written into the device, D[8:0] remains unaltered.
H
H
L–H
–
No data is written into the devices during this portion of a write operation.
H
H
–
L–H No data is written into the devices during this portion of a write operation.
Notes
3. X = “Don't Care,” H = Logic HIGH, L = Logic LOW,
↑represents rising edge.
4. Device powers up deselected with the outputs in a tristate condition.
5. “A” represents address location latched by the devices when transaction was initiated. A + 1, A + 2, and A + 3 represents the address sequence in the burst.
6. “t” represents the cycle at which a read/write operation is started. t + 1, t + 2, and t + 3 are the first, second and third clock cycles respectively succeeding the “t” clock cycle.
7. Data inputs are registered at K and K rising edges. Data outputs are delivered on K and K rising edges as well.
8. It is recommended that K = K = HIGH when clock is stopped. This is not essential, but permits most rapid restart by overcoming transmission line charging symmetrically.
9. If this signal was LOW to initiate the previous cycle, this signal becomes a “Don’t Care” for this operation.
10. This signal was HIGH on previous K clock rise. Initiating consecutive read or write operations on consecutive K clock rises is not permitted. The device ignores the
second read or write request.
11. Is based on a write cycle that was initiated in accordance with Table . NWS0, NWS1, BWS0, BWS1, BWS2, and BWS3 can be altered on different portions of a write
cycle, as long as the setup and hold requirements are achieved.
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