Hi all eeprom

[TKS]

what could be the problem when you write something to a eeprom and you read another symbol from it ..??


i use a 20Mhz (osc) pic could it be the bus speed to high..???


TKS

 

[Nigel Goodwin]

You don't say what kind of EEPROM you are trying to write, but I'm presuming it's an I2C one?. A 20MHz PIC can certainly write out faster than an I2C EEPROM can receive it, your code should be written accordingly, bearing in mind the speed limitations of the EEPROM - you can get those details from the datasheet.

You could also have a problem with your I2C routines, have a look at my I2C tutorial for software I2C code which I know works. If you're trying to use the I2C hardware in the 16F877, I have heard it's very difficult to get working, and that the application notes from MicroChip don't work.

 

[TKS]

...

i'm using

pic compiler and i just grabbed 2 ports who where free..

(d.0 & d.1)

and wired it up like your tut (whit the 9K res..)

i think its the speed i will write my own routine.. whit delays..

ionstead of the basic commands..

(in the help i read something about the speed limit)
but i turned the slof_bus=on ..i will see..

TKS

 

[StupidDum]

Try to put longer delay. PIC at 20Mhz is much faster then EEPROM .
I now face a problem on I2C.

I have written code for Atmel 24C64 i2c EEPROM, it works just fine.
Now i use Microchip 24LC64, but that just wont work.
I've checked the timing spec, both are almost identical.
I'd appreciate it if anyone could tell me the reason.

 

[TKS]

i also have

lying a pair of those atmels around...

i think it are the config bits..??

or something near like the control byte..???


TKS