Kevan:
Maybe some clues will surface by looking at the following...

1) Test by adjusting the spacing between the characters sent from the PC end. Maybe there is an issue of having the two bytes sent back to back. Increase the spacing by a bit time and try again.

2) Is your processor able to generate an accurate baud rate at 115200 bps ? Sometimes the divisor for real high baud rates can be hard to achieve exactly.

3) Have you selected a crystal frequency that permits the baud rate to be exact?

4) Are you able to probe the register contents and microcontroller memory data content as a post mortum analysis after the serial port has appeared to lockup? Maybe you have a coding problem that exhibits itself only when two serial interrupts happen right after each other.

5) Have you looked to see if if the microcontroller manufacturer has an errata sheet for your part?


Michael Karas