I'm using an EFM8LB11F32E-QFP32 because it has four DACs. DAC0 and DAC1 work as expected, but I can't get DAC2 or DAC3 to output anything! The specific problem is that the enable bits in DAC2CF0 and DAC3CF0 are always zero. I can try setting them in the debugger, but as soon as I step they get cleared. The RSTMD bits also clear themselves. Is there some for of protection on these SFRs?
I did theorise that some ISR is buggy and isn't setting the SFRPAGE correctly, but disabling all the interrupt sources hasn't made any difference.
Doh, I need to use an EFM8LB12, not an EFM8LB11 if I need four DACs. My only excuse is that it's buried in the datasheet, no mention in the reference manual.