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Write cycle descriptions – Cypress CY7C1268V18 User Manual

Page 10

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CY7C1266V18, CY7C1277V18
CY7C1268V18, CY7C1270V18

Document Number: 001-06347 Rev. *D

Page 10 of 27

Write Cycle Descriptions

The write cycle description table for CY7C1266V18 and CY7C1268V18 follows.

[2, 8]

BWS

0

/

NWS

0

BWS

1

/

NWS

1

K

K

Comments

L

L

L–H

During the data portion of a write sequence

:

CY7C1266V18

− both nibbles (D

[7:0]

) are written into the device.

CY7C1268V18

− both bytes (D

[17:0]

) are written into the device.

L

L

L-H During the data portion of a write sequence

:

CY7C1266V18

− both nibbles (D

[7:0]

) are written into the device.

CY7C1268V18

− both bytes (D

[17:0]

) are written into the device.

L

H

L–H

During the data portion of a write sequence

:

CY7C1266V18

− only the lower nibble (D

[3:0]

) is written into the device, D

[7:4]

remains unaltered.

CY7C1268V18

− 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

:

CY7C1266V18

− only the lower nibble (D

[3:0]

) is written into the device, D

[7:4]

remains unaltered.

CY7C1268V18

− 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

:

CY7C1266V18

− only the upper nibble (D

[7:4]

) is written into the device, D

[3:0]

remains unaltered.

CY7C1268V18

− 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

:

CY7C1266V18

− only the upper nibble (D

[7:4]

) is written into the device, D

[3:0]

remains unaltered.

CY7C1268V18

− 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.

Write Cycle Descriptions

The write cycle description table for CY7C1277V18 follows.

[2, 8]

BWS

0

K

K

Comments

L

L-H

During the data portion of a write sequence

, the single byte (D

[8:0]

) is written into the device.

L

L-H

During the data portion of a write sequence

, the single byte (D

[8:0]

) is written into the device.

H

L-H

No data is written into the device during this portion of a write operation.

H

L-H

No data is written into the device during this portion of a write operation.

Note

8. Assumes a write cycle was initiated per the

Write Cycle Descriptions

tables. NWS

0

, NWS

1

, BWS

0

, BWS

1

, BWS

2

, and BWS

3

can be altered on different portions

of a write cycle, as long as the setup and hold requirements are met.

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