I've recently started building stuff with some ATtiny15 I bought long ago. The chips are still in the tube I bought them in, new, from Arrow. I designed the board so I could program the completed boards with ISP.
But on my completed boards I find that SPIEN isn't programmed (serial programming not enabled). I'm using the 6-pin interface ("ISP6PIN") on my STK500. I've had to first enable SPIEN with high-voltage programming and then each chip programs properly with the 6-pin cable, in my target.
This wouldn't bother me much, but my parts are surface mount. :?
I think I can rule out the STK500 messing with the fuses because after I fix it, the fuse doesn't get messed up again.
All of the affected parts read a signature of 0xFF 0xFF 0xFF, and the oscillator calibration byte is reported 0xFF.
I've searched for this problem and can't find any reference to similar problems. Is there a common error that I could be making? Did any early date codes have this issue?
STK500 (hardware 0x02, firmware 0x020a)
ATtiny15L marked on top:
ATMEL119 TINY15L (delta)1SC
marked on underside: