Hardware breakpoint registers in PIC18F2550/PIC18F4550

[ebjoew]

I want to access the hardware breakpoint registers in a PIC18F2550 or PIC18F4550 from my own assembly language program. These registers are only functional in debug mode and probably only when the Shadow bit in the Debug register (0xFD4) is set to a one. I have seen how to access them on PIC18F452 but the PIC18F2550/PIC18F4550 must work somewhat differently. I have determined experimentally that 0xFB9 is probably involved but I do not know exactly how just yet. Do you have any info that might help?

 

[ebjoew]

After further investigation, I can now answer my own question. The additional breakpoint registers are located in the same addresses where they are in the PIC18F452. I thought they could not be there since there are "implemented" SFRs at those addresses. However, when the Shadow bit in the Debug register is set to a 1 while in Debug mode, those overlapping "implemented" registers disappear and the breakpoint registers appear in their place. Thanks to anyone who puzzled over this.

 

[Leros]

This isn't a great forum for embedded development.

I know AVR Freaks is a great place for AVR development. They pointed me to Microchip's forum for PIC: http://www.microchip.com/forums/Default.aspx?