Cypress CY7C145 Pin Definitions Left Port Right Port Description, Selection Guide Description

Left Port

Right Port

Description

I/O0L−7L(8L)

I/O0R−7R(8R)

Data bus Input/Output

A0L−12L

A0R−12R

Address Lines

L

R

Chip Enable

CE

CE

L

R

Output Enable

OE

OE

L

R

Read/Write Enable

R/W

R/W

L

R

Semaphore Enable. When asserted LOW, allows access to eight semaphores. The three least signif-

SEM

SEM

icant bits of the address lines will determine which semaphore to write or read. The I/O0 pin is used

when writing to a semaphore. Semaphores are requested by writing a 0 into the respective location.

L

R

Interrupt Flag.

L is set when right port writes location 1FFE and is cleared when left port reads

INT

INT

INT

location 1FFE. INTR is set when left port writes location 1FFF and is cleared when right port reads

location 1FFF.

L

R

Busy Flag

BUSY

BUSY

Master or Slave Select

M/S

VCC

Power

GND

Ground

Table 2. Selection Guide

Description

7C144-15

7C144-25

7C144-35

7C144-55

Unit

7C145-15

7C145-25

7C145-35

7C145-55

Maximum Access Time

15

25

35

55

ns

Maximum Operating Current

220

180

160

160

mA

Maximum Standby Current for ISB1

60

40

30

30

mA

Document #: 38-06034 Rev. *D

Page 3 of 21