Jerry Messina

As I do not understand how the start and end points are measured. In general, the benchmarks all use TMR1 to measure the code execution... the timer is started before the various routines, stopped afterwards, and the results shown on that web page. There are links to the source code used for the tests. Keep in mind that comparison was done in 2008, so a lot has changed since then!

This may be a red herring and I didn't try to track this down, but looking at the asm output with GC v1.01061, as part of ReadAD10 I noticed there are two writes to the ADFM0 bit but none to the ADFM1 bit: SYSSELECTEND1 000000 0103 BANKSEL ADCON0 0003F8 99F3 BCF ADCON0,ADCS,BANKED 0003FA 0E01 MOVLW 1 0003FC 6FFA MOVWF ADCLK,BANKED 0003FE 99F3 BCF ADCON0,ADCS,BANKED 000400 0E0F MOVLW 15 000402 6FFA MOVWF ADCLK,BANKED 000404 95FA BCF ADCLK,ADCS2,BANKED 000406 93FA BCF ADCLK,ADCS1,BANKED 000408 81FA...

oops, yes. DACxCON0 should actually be DACxCON

So, after playing around with a standalone 18F26Q71 I think I finally made some sense out of how the DACs work. It certainly didn't match the way I originally read the datasheet, but here goes: Even though there are 3 DACs with 2 selectable output pins, once you enable any DAC output on RA2/RB7 then the DAC with the highest priority will appear on one or both of the enabled output pins, with DAC1>DAC2>DAC3. In effect there's only a single DACOUT, and if you want to use the others externally then...

in every two seconds both DACs drops to 0V for 10ms. Do you have the WDT disabled? In your setup above, what pins are DACs 2 and 3 being routed to? Could you show the OPA1 register settings? I'd like to try the same thing...

in every two seconds both DACs drops to 0V for 10ms. Do you have the WDT disabled? In your setup above, what pins are DACs 2 and 3 being routed to? I'd like to try the same thing...

Evan, I'll check that out when I get a chance... sort of busy at the moment. I take back come of what I said in my previous post. While I can route DAC1 out the OPA1OUT, there's still some sort of funny interaction between the DACs... I can't get more than 1 DAC working at a time. I don't know if it has to do with using the 18F56Q71 Curiosity Nano and its builtin debugger or not. I have some 26Q71 around here somewhere... I'll try the same thing using it standalone and see if it's a debugger limitation...

Evan, I'll check that out when I get a chance... sort of busy at the mement. I take back come of what I said in my previous post. While I can route DAC1 out the OPA1OUT, there's still some sort of funny interaction between the DACs... I can't get more than 1 DAC working at a time. I don't know if it has to do with using the 18F56Q71 Curiosity Nano and its builtin debugger or not. I have some 26Q71 around here somewhere... I'll try the same thing using it standalone and see if it's a debugger limitation...