24LC256 wrong address at reading

[falingtrea]

Hello all,
I wonder if someone can help me with this problem.

I'm storing manualy some values to 24LC256 with an external programmer and editor like this :

:020000040000FA                                                ' THis line was from a blank memory - not changed
:10000000 48 45 4C 4C 4F 21 FF FF 4B 4D 31 37 57 53 FF 00  'This is the line I edit with my values
>         0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
:10001000 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF  F0    'All zeros
>         0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F  cksum
:10002000 FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFE0    'All zeros
...........continues.......
:107FF000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF91    'Last line at address 7FF0
:00000001FF                                                        ' THis line was from a blank memory - not changed

Fanis

Looks like you are one byte short on the line you edited. Each line should be 16 bytes plus a checksum. What also looks odd is that the address jumps by
0x1000 (4k) per line and not 0x10 (16).

Most good programmers have an editor built in. You would be better off using the editor to change the data and then save it off in a hex format instead of trying to edit the hex file. That way the per line check sum would be correct.

[SteveB]

One thing I see, is you keep writing over the top of the array "TEXT". Also, you don't need the FOR...NEXT loop to read sequentually.

Try just this:

I2CRead memSDA,memSCL,$A1,addr,[STR TEXT\14]  'Addr is a WORD, with initial value of $0000

This will read the first 14 bytes of the array.
To output try this:

TEXT2   VAR TEXT[8]
serout2 lcdp,lcds,[i,line1,"LOC : ",STR TEXT\6, "  ",STR TEXT2\6 ]             ' Display

[SteveB]

One other item. You have this comment: '$A0 does the same as $A1

I'm assuming this is a reference to the "Control" byte in the command.

The reason for this, is that the control byte for the EEPROM is $1010XXXR

The high nibble is $A
The low nibble is dependent of how the phyical chip select pins are wired. I'm pretty sure you have those either wired to GND or floating. This leaves the two possible values of $A0 or $A1, depending on the last bit. However, the last bit is dependent on whether you are reading or writing, and is controlled by PBP. So, it won't matter what you use there, as long as the 7 MSBs are correct.