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COMMERCIALTEMPERATURERANGE

IDT72V70190 3.3V TIME SLOT INTERCHANGE

DIGITAL SWITCH 256 x 256

PIN DESCRIPTION

SYMBOL

NAME

I/O

DESCRIPTION

GND

Ground.

Ground Rail.

Vcc

Vcc

+3.3 Volt Power Supply.

TX0-7

TX Output 0 to 7

O

Serial data output stream. These streams have a data rate of 2.048 Mb/s.

(Three-state Outputs)

RX0-7

RX Input 0 to 7

I

Serial data input stream. These streams have a data rate of 2.048 Mb/s.

F0i

Frame Pulse

I

and GCI specifications.

FE

Frame Evaluation

I

This pin is the frame measurement input.

CLK

Clock

I

Serial clock for shifting data in/out on the serial streams (RX/TX 0-7). This input accepts a 4.096 MHz clock.

RESET

Device Reset

I

This input (active LOW) puts the IDT72V70190 in its reset state that clears the device internal counters, registers

(Schmitt Trigger Input)

and brings TX0-7 and microport data outputs to a high-impedance state. The time constant for a power up

reset circuit must be a minimum of five times the rise time of the power supply. In normal operation, the

RESET

pin must be held LOW for a minimum of 100ns to reset the device.

A0-7

Address 0-7

I

When non-multiplexed CPU bus operation is selected, these lines provide the A0-A7 address lines to the internal

memories.

DS/

RD

Data Strobe/Read

I

For Motorola multiplexed bus operation, this input is DS. This active HIGH DS input works in conjunction with

CS to enable the read and write operations. For Motorola non-multiplexed CPU bus operation, this input is DS.

This active LOW input works in conjunction with

CS to enable the read and write operations. For Intel multiplexed

bus operation, this input is

RD. This active LOW input sets the data bus lines (AD0-7, D8-15) as outputs.

R/

W / WR Read/Write / Write

I

In the cases of Motorola non-multiplexed and multiplexed bus operations, this input is R/

W. This input controls

the direction of the data bus lines (AD0-7, D8-15) during a microprocessor access. For Intel multiplexed bus

operation, this input is

WR. This active LOW input is used with RD to control the data bus (AD0-7) lines as inputs.

CS

Chip Select

I

Active LOW input used by a microprocessor to activate the microprocessor port of IDT72V70190.

AS/ALE

Address Strobe or

I

This input is used if multiplexed bus operation is selected via the IM input pin. For Motorola non-multiplexed

Latch Enable

bus operation, connect this pin to ground.

IM

CPU Interface Mode

I

When IM is HIGH, the microprocessor port is in the multiplexed mode. When IM is LOW, the microprocessor

port is in non-multiplexed mode.

AD0-7

Address/Data Bus 0 to 7 I/O

These pins are the eight least significant data bits of the microprocessor port. In multiplexed mode, these pins

are also the input address bits of the microprocessor port.

D8-15

Data Bus 8-15

I/O

These pins are the eight most significant data bits of the microprocessor port.

DTA

Data Transfer

O

This active LOW output signal indicates that a data bus transfer is complete. When the bus cycle ends, this pin

Acknowledgment

drives HIGH and then goes high-impedance, allowing for faster bus cycles with a weaker pull-up resistor. A

pull-up resistor is required to hold a HIGH level when the pin is in high-impedance.

CCO

Control Output

O

This is a 4.096 Mb/s output containing 512 bits per frame respectively. The level of each bit is determined by

the CCO bit in the connection memory. See External Drive Control Section.

ODE

Output Drive Enable

I

This is the output enable control for the TX0 to TX7 serial outputs. When ODE input is LOW and the OSB

bit of the IMS register is LOW, TX0-7 are in a high-impedance state. If this input is HIGH, the TX0-7

output drivers are enabled. However, each channel may still be put into a high-impedance state by using the

per channel control bit in the connection memory.