Read/Write to 0x8000-0xFFFF may cause damage to the chip #21
Description
I'm not totally sure but my AT28C256 seems damaged. Adresses 0x7FE0 and 0x7FF0 returns 00 and when writting to them, the value is written to the next byte (respectively 0x7FE1 and 0x7FF1), and the same for 0x7FE2-0x7FEE and 0x7FF2-0x7FFE. Write 0x7FEF and 0x7FFF does nothing. I first though my wiring had an issue but everything seems fine when I read/write in 0X0000-0x7FDF so I guess my eeprom is damaged.
I guess that I damaged it trying to write at adresses > 0x7FFF because the Output Enable pin is then true whatever the outputEnable parameter is (I did that by mistake with a copy/paste of a write loop with base<=xxx where I replaced xxx by 32768). I think a simple address&=0x7FFF; at the beginning of the setAddress function would be more secure.
But again, not sure it was the problem but the fix is safe...