I have some printed circuit boards of a device that is no longer manufactured. I need to repair these boards but there is no replacement for them. I can make other boards, buy the components, but I can not get the firmware, the microcontroller is a STC 89C58RD.

I found a datasheet:


As I could see it can be programmed by serial RS232 interface. I looked for a programmer but I just find this document in chinese(I'm not sure) as following :


I already read and study a bit about JTAG standard and the TAP controller state machine to do a similar job with a Motorola Microcontroller, but I would like to know if someone know this microcontroller STC 89C58RD or has a tip about how to perform this task.

  • I need to read MCU 15W204S please
    – Younes Dib
    Commented Sep 3, 2020 at 15:32
  • @YounesDib it’s best to ask a new question if you have a specific enquiry.
    – David
    Commented Sep 3, 2020 at 21:31

2 Answers 2


To program this MCU try using the programmer software at this site: http://www.stcmicro.com/rjxz.html

Use USB to serial TTL to flash the code.

Hope this helps


I was doing a similar research and apparently there's no way to read it. STC says that it's a "feature" of their microcontrollers, the bootloader protects the code.

Links related to this question for anyone who might be interested: https://github.com/grigorig/stcgal/issues/7 https://embdev.net/topic/404939 https://github.com/grigorig/stcgal/issues/18

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.