Good afternoon,
I'm trying to register a serial (com-0) interrupt using uVision 3 on the Cypress FX2LP. The code compiles fine, but the linker warns:
WARNING L16: UNCALLED SEGMENT, IGNORED OVERLAY PROCESS SEGMENT: ?PR?COM_ISR?MAIN
My ISR looks like this:
static void com_isr (void) interrupt 4 { char c; if (RI) { c = SBUF0; // read character RI = 0; // clear interrupt request flag if (istart + ILEN != iend) { inbuf[iend++ & (ILEN-1)] = c; } } if (TI != 0) { TI = 0; // clear interrupt request flag if (ostart != oend) { // if characters in buffer and SBUF0 = outbuf[ostart++ & (OLEN-1)]; // transmit character sendfull = 0; } else { // if all characters transmitted sendactive = 0; // clear 'sendactive' } } }
This code is pretty much copy and pasted from the Keil Help section on Serial Transmission.
This ISR is not being called, even with IE=0x80 (to enable global interrupts) and ES0 = 1 (to enable serial 0 interrupts). Does anyone have any suggestions?
Thanks,
Montana
That's not relevant here, as interrupts work entirely differently in C51.
In C51, it's the interrupt keyword that tells the compiler 1. to generate the ISR entry & exit code, and 2. to insert an entry at the specified location in the vector table.
This does, however, make it stange that there should be an "uncalled function" warning - since the interrupt keyword should be telling the compiler to create the "call" itself!
You haven't set the option to disable vector table generation, have you...?