How to read firmware from an STC microcontroller?

Question

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:

http://www.stcmcu.com/datasheet/stc/STC-AD-PDF/STC89C58RD+-english.pdf

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 :

https://www.stcmicro.com/pdf/STC-ISP-Programmer_V6.0_Manual.pdf

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.

Answer 1

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

Answer 2

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