2

IDT728981 Time Slot Interchange

Digital Switch 128 x 128

35

34

33

32

31

30

29

37

36

5703 drw02

INDEX

38

39

11

12

13

14

15

16

17

9

10

8

7

TX3

GND

RX3

F0i

C4i

DTA

ODE

1

2

40

39

TX0

3

38

TX1

4

37

TX2

5

36

TX3

6

35

7

34

8

33

9

32

10

31

GND

11

30

12

29

CS

13

28

14

27

5703 drw04

15

16

17

18

19

20

26

25

24

23

22

21

RX1

RX2

RX3

F0i

R/

W

DS

C4i

RX0

PIN CON.IGURATION

PIN DESCRIPTIONS

PLCC: 0.05in. pitch, 0.65in. x 0.65in.

(J44-1, order code: J)

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PLASTIC DIP: 0.10in. pitch, 2.05in. x 0.60in.

(P40-1, order code: P)

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NOTE:

1. DNC - Do Not Connect

SYMBOL

NAME

I/O

DESCRIPTION

GND

Ground.

Ground Rail.

+5.0 Volt Power Supply.

DTA

Data Acknowledgment

O

This active LOW output indicates that a data bus transfer is complete. A pull-up resistor is required at this

(Open Drain)

output.

RX0-3

RX Input 0 to 3

I

Serial data input streams. These streams have 32 channels at data rates of 2.048 Mb/s.

F0i

Frame Pulse

I

C4i

Clock

I

4.096 MHz serial clock for shifting data in and out of the data streams.

A0-A5

Address 0 to 5

I

These lines provide the address to IDT728981 internal registers.

DS

Data Strobe

I

This is the input for the active HIGH data strobe on the microprocessor interface. This input operates with

CS to enable the internal read and write generation.

R/

W

Read/Write

I

This input controls the direction of the data bus lines (D0-D7) during a microprocessor access.

CS

Chip Select

I

Active LOW input enabling a microprocessor read or write of control register or internal memories.

D0-D7

Data Bus 0 to 7

I/O

These pins provide microprocessor access to data in the internal control register. Connection Memory HIGH,

Connection Memory LOW and data memory.

TX0-3

TX Outputs 0 to 3

O

Serial data output streams. These streams are composed of 32, 64 Kbit/s channels at data rates of 2.048 Mb/s.

(Three-state Outputs)

ODE

Output Drive Enable

I

This is an output enable for the TX0-3 serial outputs. If this input is LOW, TX0-3 are high-impedance. If this is

HIGH, each channel may still be put into high-impedance by software control.

29

28

27

26

25

24

23

31

30

5703 drw03

INDEX

32

33

5

6

7

8

9

10

11

3

4

2

1

TX3

GND

RX3

F0i

C4i

PQFP: 0.80mm pitch, 10mm x 10mm

(DB44-1, order code: DB)

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