Flash programming, strange issue

[spectrum70]

Hello all,

i am experiencing a strange problem programming a parallel flash memory SST29VF3201B (2Mega x 16bit words) from a coldfire processor.

i try to explain what happen

1) using the constructor programming algorithm, i erase the flash, this succeded, i have all the 16bit words to 0xFFFF.
2) using the write sequence (0x555:0xAA, 0x2AA:0x55, 0x555:0xA0, addr:word) i write a word of value 0x0000 at 0x0000 address.
The strange result is that the word is written 3 times at addr 0, 8 and 32 ..

with a breakpoint just after the write, memory dump shows:

0000FFFF FFFFFFFF FFFFFFFF FFFFFFFF 0000FFFF FFFFFFFF FFFFFFFF FFFFFFFF
FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF
0000FFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF ....

Any idea/help is really appreciated.
thanks,
spectrum

 

[slugworth]

2) using the write sequence (0x555:0xAA, 0x2AA:0x55, 0x555:0xA0, addr:word) i write a word of value 0x0000 at 0x0000 address.

Your adresses are wrong.
They should be 0x5555 then 0x2AAA then 0x5555

 

[spectrum70]

no, they are as per datasheet.

I solved:
i was writing right, but the ide was reading the same value in other memory location also. Was 2 pins of the flash not well soldered


many thanks,