MOSA

MS6821

4 Stereo inputs / 2W PA output integrated Audio DAC and Volume Control

REV 3

16/29

www.mosanalog.com

BUS INTERFACE

Data are transmitted to and from the MCU to the MS6821 via the SDA and SCL. The SDA and SCL make up the

BUS interface. It should be noted that pull-up resistors must be connected to the positive supply voltage.

SDA (Serial Data Line)

Rp

Rp

SCL (Serial Clock Line)

Pull up resistors

V

DD

MCU

MS6821

I

The format consists of the following:

‧

A START condition

‧

A chip address byte including the chip address. (7bits)

‧

‧

The chip must always acknowledge the end of each transmitted byte.

‧

A data sequence (N-bytes + Acknowledge)

‧

A STOP condition

SCL

SDA

1-7

8

9

1-7

8

9

9

8

1-7

S

P

ADDRESS

R/ W

ACK

ACK

ACK

DATA

DATA

START

CONDITION

STOP

CONDITION

I

88H

1000

00

10

7 bits address

W