I need help with i2c memory

[-c3-]

hey! its working,
the problem i was having was in declaring tris when reading/writing to the memory. ive got it working now and am very happy. thankyou all for the help, heres my current code,

trisb=%00000010 'read i comment one out
'trisb=%00000001 'write
addr var byte
sda var PORTB.0
scl var PORTB.1
cont con %10100000
x var byte 'test data
y var byte 'read data


'x=%00000001 'test data is the number 0'

addr=0
loop:

'I2Cwrite sda,scl,cont,(addr),[x] 'comment out when reading
'pause 20
i2Cread sda,scl,cont,addr,[y] 'should read the data
pause 20
serout portb.2,4,[254,1]

serout Portb.2,4,["y=",#y," x=",#x," a=",#addr] 'visual verification
addr=addr+1
'x=x+%00000001

if addr=255 then end

goto loop

end

[DynamoBen]

I have used external I2C EEProm on a number of projects and have NEVER had to change the TRIS statement to get things to work. Also you STILL have you address variable as a byte, it needs to be a word.

There is still something horribly wrong with either the software or hardware.

[Darrel Taylor]

In your first message, you mentioned 2 different EEPROMs.

24AA512 and 24c01

Which one are you currently having success with?

The 24AA512 is a 64Kx8 device and needs a WORD sized address.
The 24c01 is a 128x8 and only needs a BYTE sized address.

My guess is that you're using the 24c01.

If that's the case, then your test routine loops through 255 address locations, which is double the actual size of the EEPROM. Anything above 127 will loop around and display the first 128 again. Of course, it's just a test routine, but just wanted to let you know.

Best regards,
   Darrel