probably something completely stupid, but I seem to be unable to get an attiny12 to behave properly:
I wrote this crude test program:
mov r2, r1
in r16, portb
out portb, r16
Fuse Bits: Mode 1, int. RC / 67ms, SPI & Reset enabled, BOD disabled.
The circuit is just a pull-up on Reset, and a few LEDs with series resistors on PB0-PB4...
Programming all works fine, but the LEDs all indicate High on all pins, no change...
Also tested with LEDs going to VCC or GND, and with a driver transistor in between...
Programming the chip workes fine each time.
What did I miss?