6

¡ Semiconductor

ML7021

(3/4)

Pin

Symbol

Type

Description

11

SYNC

I

12

SOUT

O

13

ROUT

O

17

X1/CLKIN

I

18

X2

O

16

HD

I

Sync signal for transmit/receive serial data.

This pin uses the external SYNC or SYNCO.

Input the PCM CODEC transmit/receive sync signal (8 kHz).

Transmit serial data.

Outputs the PCM signal synchronized to SYNC and SCK.

This pin is in a high impedance state during no data output.

Receive serial data.

Outputs the PCM signal synchronized to SYNC and SCK.

This pin is in a high impedance state during no data output.

Controls the howling detect function. This pin detets and cancels a howling

generated during hand-free talking for acoustic system.

This function is used to cancel acoustic echoes.

• Single Chip or Master Chip in a Cascade Connection

"L": Howling detector ON

"H": Howling detector OFF

• Slave Chip in a Cascade Connection

Fixed at "L"

External input for the basic clock (17.5 to 20 MHz) or for the crystal

oscillator.

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

clock of 19.2 MHz.

Crystal oscillator output.

Used to configure the oscilation circuit.

Refer to the internal clock generator circuit example.

When inputting the basic clock externally, insert a 5 pF capacitor with

excellent high frequency characteristics between X2 and GND.

20

PWDWN

I

Power-down mode control when powered down.

"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, MCKO

"H": OF1, OF2, X2

Holds the last state : WDT, IRLD

Reset after the power-down mode is released.