Nor Flash

[jazu_4743001]

I am using S29GL032N.

Most the operations (block erasing, write, chip erasing) require a command sequence by writing some specific values to some specific addresses. For example, to ease a block starting at 0x10000, we need :

write 0x555  with 0xAA

write 0x2AA with 0x55

write 0x555 with 0x80

write 0x555 with 0xAA

write 0x2AA with 0x55

write 0x10000 with 0x30

This works.

But today I accidently find the operation still work if I change some MSBs of the address to 1 instead of 0.  For example, the below sequence:

write 0xFFD55  with 0xAA

write 0xFFAAA with 0x55

write 0xFFD55 with 0x80

write 0xFFD55 with 0xAA

write 0xFFAAA with 0x55

write 0x10000 with 0x30

It looks like that only bit 0~10 matter. Is this true？ Is this a common feature for NOR flash?