Hello,
maybe, someone could help, I'm experiencing a problem with storing any data to EEPROM of HZ256 using same algorithm, as I use for e.g. DT256 (and working well).
I tried to burn some pattern into EEPROM and result is, whole EEPROM array is $00. Erase seems to work well, after that I can read $FF.
My HZ256 is member of 3L16Y maskset (QAD0620) and existing errata doesn't describe such a problem.
I'll keep on to find the reason, maybe I omitted some important difference in programming algo.