Sir,
Sometimes our product which used 9200 MCU outputs CCCCCCCCCCCCCC out of DEBUG SERIAL Port when powerup.This is a mistake.It seems to startup from intel rom,but I hope from FLASH where our application stayed.
Plase help me,thanks.
smiletan

Seeing 'C' characters coming out periodically suggests it is waiting for an X-Modem transfer.

Does it boot sometimes, and not others, your message is not clear? Do you have bugs in your code that could cause this? Under what conditions does it actually work?

Do you do any check-summing in your boot code to check the integrity of the ROM? What does it do if it fails?

What ROM? Do you have a part number and timing specification? How's it connected, and what speed is the 9200 running at?

Have you stepped through the code with a JTAG debugger, can you see where it is failing?

In summary, you're going to have to provide a lot more detailed explanation if you expect anyone to troubleshoot this.