Tel : 886-2-29162151

Fax: 886-2-29174598

URL: http://www.princeton.com.tw

MP3 Audio Decoder

PT8401

PT8401 v 1.3

Page 7

Updated March 2002

Princeton Technology Corp.

0

1

Left

Left

Right

Right

The default output waveform is show in Figure 4. Each PCM sample consists of a 2's complement

16-bit MSB-first data and another 16 bits of blank data forming 32 bits data in each channel.

ADQO is valid at the rising edge of ACKQO and the last bit of a sample is aligned with the edges of

ALRQO. However, PT8401 offers 3-bit, eight combinations to fit different kinds of audio DACs via

the start-up configuration or command registers.

Bit 0 : 32/16 bits per sample selection. If 16-bit per sample is selected, each channel contains only

16-bit MSB first data.

Bit 1 : ALRQO Left Channel indicating Low/High selection.

Bit 2 : Delay Selection. When this bit is set, the transition of ALRQO is one clock cycle earlier.

This is called I

FIRST SERIAL BITSTREAM INPUT INTERFACE

Serial Bitstream (regardless of whether it is an MPEG audio or ADPCM speech bitstream) comes from

this port. The following three signals are needed to make a complete transfer.

BD1: Serial Bitstream Data Input.

BCK1: Bit Clock Input.

B_ENA1: Serial Data Enable Signal, Active: Low

DATA_REQ : Data Request Signal.

ALRQO

Left Channel

Right Channel

14 13 12 11

15

3 2 1 0

4

14 13 12 11

15

3 2 1 0

4

14 13 12

5

15

3 2 1 0

4

14 13 12

5

15

3 2 1 0

4

0

1

ADQO