It seems that doing a LD R24,Z+ on an ATtiny26 resets the high byte of Z to 0x00. This is totally unexpected to me"” the tiny26 data sheet says that Z is a full 16-bit register, but even on parts for which the postincrement only affects 8 bits, it just ignores the high byte, right? Is this a silicon bug / defective part, or did I miss something in the datasheet?
FWIW, my tiny26 is marked 0533D, presumably that means revision D from 2005 wk. 33?