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TDK 73M2901/5V User Manual

Page 4

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73M2901/5V
Advanced Single
Chip Modem

4

PIN DESCRIPTIONS

(continued)

OSCILLATOR PIN DESCRIPTION

PIN NAME

32-PIN 44-PIN TYPE DESCRIPTION

OSCIN

24

26

I

Crystal input for internal oscillator, also input for external
source.

OSCOUT

23

25

O

Crystal oscillator output.

DIGITAL INTERFACE PIN DESCRIPTION

PIN NAME

32-PIN 44-PIN TYPE DESCRIPTION

RESET

13

9

I

Resets 73M2901/5V

RXCLK

31

36

O

Receive Data Synchronous Clock

RXD

30

35

O

Serial output to DTE.

TXCLK

28

31

O

Transmit Data Synchronous Clock

TXD

27

30

I

Serial data input from DTE.

USR10

12

8

I/O

This pin can optionally be configured as an active low detect
pin. This can be used to implement such functions as “parallel-
pick-up”, “line-in-use”, or “seize” detect.

USR11

11

7

I/O

Programmable I/O port. This pin can ooptionnaly be used to
control an external switch for Caller ID decoding operations.

RTS (USR12)

10

6

I

Request to Send

CTS (USR13)

9

5

O

Clear to Send

DSR (USR14)

8

4

O

Data Set Ready

DCD (USR15)

7

3

O

Data Carrier Detect

RI (USR16)

4

43

O

Ring Indicator

RELAY (USR17)

3

40

O

Relay driver output