MCD221

2–5

MOTOROLA

FUNCTIONAL DESCRIPTION

DATA FLOW DIAGRAM

DATA INPUT (DI)

CD DATA IN

AUDIO PROCESSOR

(AP)

HOST INTERFACE

(HI)

MCD221 CIAP

EXTERNAL AUDIO IN

AUDIO OUT

68xxx

HOST INTERFACE

The MCD221 Data Flow Diagram should be used in con-

junction with the following notes which outline the function of

the various blocks within the device:

• The data input module consists of two parts; a main chan-

nel decoder and a subchannel decoder. Both decoders can

be active at the same time. The main channel decoder can

be in different modes; CD–DA mode, CD–ROM mode, or

CD–i mode.

• The audio processor module accepts an external audio

input and, after processing, generates an audio output.

• The microcode controller interface takes care of accept-

ing commands and passing data to the different parts of the

audio processing unit.

• The host interface takes care of addressing the internal

registers and buffers. The CIAP can interface with two pos-

sible hosts; a 68000 type host or a microcontroller that in-

terfaces via a serial link.