Writing into EEPROM directly through I2C Bus

[Guest]

Hi

Is it possible to write directly some data directly into the Pic Micro's internal EEPROM over the I2C Bus by an external Processor

To reframe the question, is it possible to have the following I2C operation by an external Master to slave PIC 16F819

Write <Pic-Add><PIc's EEPROM-Add> <Data>

What is the best way to do this
Any pointer on this would be of great help

Thanks & best regards,
Raghu PV

[rnielsen]

I, personally, haven't done this one before but I'm sure that it's possible. You could have your Slave I2C interrupt routine look for a certain command word and then take the data that follows it and enable a function to write that data to it's internal eeprom.

Ronald

[valemike]

Yeah, in your PIC's slave routine, then call write_eeprom(). If I had to do it, I probably wouldn't do it in the SSP ISR, but rather defer the eeprom operation once i get out of the isr.

If you're asking is it it possible for the i2c data to write directly to the eeprom, then this reminds me of DMA. And no, it's not possible. You have to go thru the SSP/MSSP module first, read the SSPBUF, then write software to store it in the appropriate eeprom location.

[Guest]

Hi ,

Thanks for the replies.

I was looking for the DMA kind of operation , so that external master CPU can write some data into the PIC without PIC's intervention

I understand now the requirement of EEPROM as it is not not directly mapped into the PIC's mem map

well, I have another question ..
Since GPR area is directly mapped into the data memory , writing a data directly into this area is possible ?

For example in the PIC 16F 819 , in Bank 1 C0 to FF is available for GPR
Can the host CPU can write any data directly into this area say by
<i2C Device address><word address-C0>,<Data> ?

Appreciate your reply

Thanks & Best regards,
Raghu PV