Hi All,
Just a week into a eZ80 project we have encountered a severe bug, severe enough to make the device useless for our use, and I wondered if anyone else has come across this.
The device is a eZ80F91, and we are using all the timers. The problem is that if your code is at an address with the low byte being
0,1,2 or 3(depending on which timer is in use), and the value on the data bus is odd (bit zero set) then a timer event will be missed. This doesn't happen often but when it does it really screws our system.
Zilog know about this, and have published the details in an errata sheet. The suggested work around is to run timers in parallel, and one of them will work when the other fails, which doesn't work for us, or to move your code so there are nop's at addresses ending in 0,1,2 or 3.
This seems to apply to date codes 0317 or later -- our devices are
0539. Calling/emailing Zilog hasn't produced any response so far.
Has anyone used this device and encountered this, and does anyone know if there has been a silicon update ?.