Cypress CY7C037V manual Non-Contending Read/Write Inputs Outputs 9 -I/O 0 -I/O, Operation, Status

CY7C027V/027VN/027AV/028V

CY7C037V/037AV/038V

Table 1. Non-Contending Read/Write

Inputs

Outputs

I/O9–I/O17

I/O0–I/O8

CE

R/W

OE

UB

LB

SEM

Operation

H

X

X

X

X

H

High Z

High Z

Deselected: Power Down

X

X

X

H

H

H

High Z

High Z

Deselected: Power Down

L

L

X

L

H

H

Data In

High Z

Write to Upper Byte Only

L

L

X

H

L

H

High Z

Data In

Write to Lower Byte Only

L

L

X

L

L

H

Data In

Data In

Write to Both Bytes

L

H

L

L

H

H

Data Out

High Z

Read Upper Byte Only

L

H

L

H

L

H

High Z

Data Out

Read Lower Byte Only

L

H

L

L

L

H

Data Out

Data Out

Read Both Bytes

X

X

H

X

X

X

High Z

High Z

Outputs Disabled

H

H

L

X

X

L

Data Out

Data Out

Read Data in Semaphore Flag

X

H

L

H

H

L

Data Out

Data Out

Read Data in Semaphore Flag

H

X

X

X

L

Data In

Data In

Write DIN0 into Semaphore Flag

X

X

H

H

L

Data In

Data In

Write DIN0 into Semaphore Flag

L

X

X

L

X

L

Not Allowed

L

X

X

X

L

L

Not Allowed

Table 2. Interrupt Operation Example (assumes

L

R=HIGH)[37]

BUSY

=BUSY

Left Port

Right Port

Function

A0L–14L

A0R–14R

R/W

L

CEL

OEL

INTL

R/WR

CER

OER

INTR

Set Right

INT

R

Flag

L

L

X

7FFF

X

X

X

X

X

L[39]

Reset Right

INT

Flag

X

X

X

X

X

X

L

L

7FFF

H[38]

R

Set Left

INT

L Flag

X

X

X

X

L[38]

L

L

X

7FFE

X

Reset Left

Flag

X

L

L

7FFE

H[39]

X

X

X

X

X

INT

L

Table 3. Semaphore Operation Example

Function

I/O0–I/O17Left

I/O0–I/O17Right

Status

No action

1

1

Semaphore free

Left port writes 0 to semaphore

0

1

Left port has semaphore token

Right port writes 0 to semaphore

0

1

No change. Right side has no write access to semaphore

Left port writes 1 to semaphore

1

0

Right port obtains semaphore token

Left port writes 0 to semaphore

1

0

No change. Left port has no write access to semaphore

Right port writes 1 to semaphore

0

1

Left port obtains semaphore token

Left port writes 1 to semaphore

1

1

Semaphore free

Right port writes 0 to semaphore

1

0

Right port has semaphore token

Right port writes 1 to semaphore

1

1

Semaphore free

Left port writes 0 to semaphore

0

1

Left port has semaphore token

Left port writes 1 to semaphore

1

1

Semaphore free

Notes

37.A0L–15Land A0R–15R,FFFF/FFFE for the CY7C028V/038V.

38.If BUSYR=L, then no change.

39.If BUSYL=L, then no change.

Document #: 38-06078 Rev. *B Page 15 of 18

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