I did a design with the SO8QA2 processor, everything was fine until i realise the low voltage reset is ON during boot up, so if you run a 1.8V regulator it will not always boot depending on 1.7V or 1.81V. The processor runs down fine at 1.6V, but i cant get it to boot because of SPMSC1 LVDRE (low voltage reset enable). If this bit was OFF during boot, i could disable it and i would be fine, but its not, so this processor seems to be useless at 1.8V.
Any suggestions on getting this processor to work? Or, another very low cost processor similar that will do the job? (has to be about USD$0.50, 70c max).
The application is a very very low power (100uA) external watch dog, it just checks 2 pins are toggling and sets an output if they are not for 1 second, VERY simple external watch dog.