SPI Problem with ATMEL AT25F1024A [solved]

[2pi]

hello!
i tried your suggestion, but it still not work.

i noticed the following effect:
i can read and write the statusregister as often i want.
i can read the ID of the chip as often i want.
i can read data from an adress, when there never was an write cycle on this adress the comeback value is 0xff.
i can program data at a adress once correctly.
when i read it back there is the correct value on this adress.
when the data on this adress is reprogrammed with another new value and newly readed there comes the value = (oldvalue (binary and) new written value) back. (in c-code: oldvalue&newvalue) this means if i write in the first write cycle 0xfe and in the second write cycle (on the same adress) 0xfd the comeback value after the second write cycle is 0xfc.
the chip erase function does not work.
the labor power supply is 3.6V and the current limitation is turned off.

so that means that i can program the seeprom only one time.
i changed the seeprom and with the new one there is the same effect.


i�ve no ideas any more what to do.

has anyone suggestions ...

greetings 2pi



!!!!!!!
i think i got it -> i read the datasheed of the seeprom a second time, before a new write cycle the page must be deleted.

ok this works now !!!

thanks to

Ttelmah
asmallri
Humberto

!!!!!!!