6.42

IDT7016S/L

High-Speed 16K x 9 Dual-Port Static RAM

Military, Industrial and Commercial Temperature Ranges

16

Truth Table IV — Address BUSY

Arbitration

NOTES:

2. "L" if the inputs to the opposite port were stable prior to the address and enable inputs of this port. "H" if the inputs to the opposite port became stable after the address and enable

outputs are drivingLOW regardless of actual logic level on the pin.

NOTES:

1. This table denotes a sequence of events for only one of the eight semaphores on the IDT7016.

Truth Table III. The left port clears the interrupt by an address location

right port must access memory location 3FFF. The message (9 bits)

at 3FFE or 3FFF is user-defined since it is in an addressable SRAM

location. If the interrupt function is not used, address locations 3FFE

and 3FFF are not used as mail boxes but are still part of the random

access memory. Refer to Truth Table III for the interrupt opera-

tion.

Functional Description

The IDT7016 provides two ports with separate control, address

and I/O pins that permit independent access for reads or writes to any

location in memory. The IDT7016 has an automatic power down

feature controlled by CE. The CE controls on-chip power down

circuitry that permits the respective port to go into a standby mode

when not selected (CE HIGH). When a port is enabled, access to the

entire memory array is permitted.

Interrupts

If the user chooses the interrupt function, a memory location

(mail box or message center) is assigned to each port. The left port

Inputs

Outputs

Function

X

X

NO MATCH

H

H

Normal

H

X

MATCH

H

H

Normal

X

H

MATCH

H

H

Normal

L

L

MATCH

(2)

(2)

3190 tbl 17

Functions

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

3190 tbl 18