I am using a Dallas 87C530 running the second serial port at 115200 baud, interrupt-driven.

I am experiencing a problem with the receive side in that when I send two or three characters in succession, the receive side somehow locks up and no further receive interrupts are ever received. The transmit interrupt however still continues to be received and processed. The first thing I do inside the ISR is check and clear the RI1 flag (using jbc RI1,label).

If I send characters more slowly, e.g. at the PC's keyboard repeat rate, there is no problem.

I've disabled Framing Error detection (and checked for FE just in case).

I've tried configuring the PC to use 2 stop bits to no avail.

The same code works on Serial Port 0!!

Any suggestions???