PT8401 Datasheet, PDF (11/28 Pages) Princeton Technology Corp – MP3 Audio Decoder

Princeton Technology Corp.
MP3 Audio Decoder
Tel : [phone]
Fax: [phone]
URL: http://www.princeton.com.tw
PT8401
Table 4. Settings for input frequency 12.288MHz.
Register Name
PLLSet
PLLFraction
Value
0x3b28
0x7e5e
The sampling frequency of ADPCM encoding is controlled by Serial Input Port 2; however, the
sampling frequency of ADPCM decoding is controlled via the setting of PLL. The microcontroller has
to be set properly to get the right listening results. The default setting for ADPCM decoding assumes
that sampling frequency is 8kHz; however, 11.025kHz and 12kHz are selectable, too.
Start-up Configuration and General Purpose IO
PT8401 offers another easy way to configure the basic start-up setting without using the external controller.
It is called “Start-up” Configuration. GPIO pins are configured as input pins before RESET. After RESET,
those values are latched to be the basic configuration of PT8401. After start-up, the GPIO pins are
configured as output pins.
START-UP CONFIGURATION
GPIO
0
1
2
3
4
5
6
7
Name
Description
SetMode "0" : MPEG Mode
"1" : ADPCM Mode
AdpcmMode "0" : Bitstream Decoding
"1" : Sample Encoding.
SP_SEL "0" : First Serial Port
"1" : Parallel Input Port Selection (only in MPEG Decoding).
Set_SAO[0] Set Serial Output Port. Same as Main Function Selection.
Set_SAO[1]
Set_SAO[2]
Set_SAI2[0] Set Second Serial Input Port. Same as Main Function Selection.
Set_SAI2[1]
PT8401 v 1.3
Page 11
Updated March 2002