RCM6000, TimerB, Step/Match Interrupt

Trying to get the Rabbit 6000 to run using the timerB step registers on the dev board for the RCM6700.
Example code

nodebug root interrupt void timerb_isr()
RdPortI(TBCSR); // clear interrupt by reading
// toggle bit PD0, flashes on dev board
WrPortI(PDDR,&PDDRShadow,PDDRShadow ^ 0x01);

// set up the PD0 on teh development board as output
BitWrPortI(PDDDR, &PDDDRShadow, 1, 0);
BitWrPortI(PDDCR, &PDDCRShadow, 0, 0);
BitWrPortI(PDFR, &PDFRShadow, 0, 0);

    // install ISR routine
SetVectIntern ( 0x0B, timerb_isr ); // set ISR

    // initialize Timer B and B1 step+match registers
WrPortI(TBCSR, NULL, 0x00);	
WrPortI(TBSL1R, NULL, 0xFF);	
WrPortI(TBSM1R, NULL, 0x00);
WrPortI(TBL1R, NULL, 0xFF);
WrPortI(TBM1R, NULL, 0x00);
WrPortI(TBCR , NULL, 0x11); 
WrPortI(TBCSR, NULL, 0x03);	


The above causes the debugger times out.

Try running the programs in samples imerB.

I would recommend writing the ISR in assembly as in the examples.

See the DC10 user manual, 13.6 Interrupt Routines in Assembly for more details.