¡ Semiconductor

MSM7603/7603B

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PIN DESCRIPTIONS (Continued)

Pin

Symbol

Type

Description

8

RST

I

9

PWDWN

I

10

HD

I

12

CLKIN

I

16

SYNCO

O

This is the input pin for the reset signal.

"L": Reset mode

"H": Normal operation mode

Due to initialization, input signals are disabled for 100 ms after reset

(after RST is returned from "L" to "H").

Input the basic clock during the reset.

Output pins during the reset are in the following sates :

High impedance: SOUT, ROUT

Not affected: SYNCO, SCKO

This is the power-down mode control pin for power down operation

"L": Power-down mode

"H": Normal operation mode

During power-down mode, all input pins are disabled and output

pins are in the following states :

High impedance : SOUT, ROUT

"L": SYNCO, SCKO

Reset after the power-down mode is released.

This pin controls the howling detect function that detects and

cancels a howling generated during hands-free talking for

acoustic system.

This function is used to cancel acoustic echoes.

"L": Howling detector ON

"H": Howling detector OFF

This is the input pin for external input for the basic clock.

Input the basic clock (17.5 to 20 MHz).

When the internal sync signal (SYNCO, SCKO) is used, input the

basic clock of 19.2 MHz.

This is the output pin for the 8 kHz sync signal for the PCM codec.

Connect to the SYNC pin and the PCMcodec transmit/receive sync

pin.

Leave open if using an external SYNC.

11

(m/A)

I

Used for MSM7603B only.

This is the input pin for m-law PCM/A-law PCM interface select

signal.

"L": A-law PCM interface

"H": m-law PCM interface

13

I

This is the power supply pin for the PLL circuit used for the basic

clock.

Insert a 0.1 mF capacitor with excellent high frequency

14

I

This is the ground pin for the PLL circuit used for the basic clock.