Dear Mr. Paul,
Sir I had been visiting your website for making an internet radio. The story is like this - I had a worldspace satellite radio receiver manufactured by BPL Sanyo India. I was using the service but unfortunately worldspace didn't gain much commercial profit from Indian and Asian market as the subscription prices were very high. So finally on dec31st they stopped broadcasting in my country. Now I was left with the receiver only but no chance to connect to the satellite radio network so one fine day I started designing an internet radio receiver using a Ethernet to serial converter and a 8051 MCU (NXP P89V51RD2BN) but I was not having the STA013 decoder, so I just opened this piece of crap and glanced the hardware and luckily I found the predecessor of STA013 - the STA003 which was developed by SGS Thomson people for use in STARMAN satellite radios so I made a circuit board for all this and I got the DAC CS4334 crystal etc from the radio pcb. Now when I was designing the PCB for this application I googled for some good references and I found your site, which is really good and informative. As is completed the hardware and started programming I rigged up the hardware and without sending the patch file I was able to play files in broadcast mode, when I uploaded the file to this STA003 chip it started working like a STA013 (as I expected) so regarding the mystery of this file - SGS Thomson people originally developed STA003 for satellite radio MPEG packet decoding and when the expected sales was not achieved they put this patch file and started selling it as STA013. You could try this just leave the DATAREQ pin (or ignore it) and tie up the SRCINT pin to +3V then boot up the chip and perform a hard reset after that just don't make any settings and simply write to the run and play registers with 0x01H and start sending the data at proper bit rate it will play the files. But in this mode the chip can support up to 128kbps only. My hardware is working fine when I uploaded a mp3 file to it using a serial port running at 115.2kbps and I tried playing files of different baud rates (i.e. 32,64,48,56,80,96,112 etc) and is working fine without any problems. I faced some problems initially regarding the serial communications as with low bit rate files the STA003 was going into a buffer over-run condition so I added a RTS/CTS handshake to resolve this problem and now my software keeps checking the DATAREQ signal and sends the proper data. I will send you the photographs of my hardware (as the thing is still not complete coz I need to add up LCD, remote, and keypad interface etc). one more thing all this time since last one week I was referring to your website for my hardware development and today when im sending you this email I finally got succeeded in my work and again when I was reading the text at your site I came across your request regarding the patch file information so I finally decided to resolve it, please find attached the STA003 datasheet for refrence. The receiver actually used 3 chipsets from SGS - STA-001 analogue front-end, STA002-Channel decoder, and STA003 MP3 decoder. The SRC INT signal is basically used to perform a small amount of compensation in the bitrate for adjusting the output PLL for DAC. As the STA002 will keep sending MPEG frames and you may find in the datasheet that it's a completely worldspace thing that it asserts the SRCINT signal every 400ms. Please update this information as any one having a worldspace receiver can easily turn it into a internet radio (standalone) or a mp3 player.