T5CKI on an 18F4431

[shaned]

I have an application that requires T5CKI to be input on pin RD0 of a PIC18F4431 - this should be the default setting for the chip according to Microchip docs.

I'm using MPLAB7.30 for software simulation support and I use the CCS plug-in to have MPLAB interoperate with the PICC compiler toolset. I'm using pch 3.226.

No matter whether I specify the SSP_RC or SSP_RD fuses (or none of these fuses at all), MPSIM always shows T5CKI associated with the alternate pin RC3. I cannot select RD0 through compilation. Even if I force the config bit in MPLAB Config Settings to RD0, as soon as I load the PICC code to start debugging, the T5CKI signal reverts to pin RC3.

I didn't find anything on the Microchip SIM/IDE message boards on this. I also scanned the PICC release mods, but didn't find anything about timer5 (though there were some references to PIC18 optomizations). Am I doing something dumb or am I running into a bug?

[shaned]

I found my problem and I've corrected it. I found a mention to the "Device Editor" in the PICC manual. There I discovered the SSP_RC and SSP_RD fuse definitions. I noticed that both mask for the bit that controls TMR0/T5CKI. However, I noticed further that both SSP_RC and SSP_RD set this TMR0/T5CKI mux bit to 1. It never gets set to 0.

I modified the SSP_RD fuse option to clear bit 4. After re-compling the project with pch, MPLAB's SIM now shows the TMR5 input set to RD0 as it should be.

(Now, is it reasonable to have the SSP_RD fuse option configure the TMR0/T5CKI mux feature? Did I overlook a more appropriate fuse label? I don't know - that's for bigger minds to decide.)

Has this already been updated in a later revision of pch?

[PCM programmer]