> Peter
> Babar

Seems, some postings are invisible ?


My suggestion:
First check, if data lines o.k.:
write 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40 and 0x80 to address 0x0000 and check, if every can be read back.

Then check the address lines:
write the values 1 ... 17 to the addresses 0x0000, 0x0001, 0x0002, ... 0x4000, 0x8000.
Then check all, if they can be read back.

Additional you can make a spike test:
Write 0xFF to address 0xFFFF and then 0x00 also to 0xFFFF. If you can both read back, you address latch seems working o.k.

There is a Dallas application note, why this can be failed under some circumstances (ALE considerations).


Peter