What is device driver?

[devendra.devgupta]

Hi friends

I have interfaced custom hardware to my embedded board, the custom hardware communicates with the board using a custom protocol over rs485 line, Now there is two level of code abstraction here

1) Code for initializing the uart, writing to uart and reading from uart for particular controller
2) Code for initializing the custom hardware using uart functions as in point 1.

I have a very basic question here which code is called device driver here. please let me know as i am little bit confused here

Thanks in advance

 

[devendra.devgupta]

i think only few people knows this difference. can any one of these few people help me as this question is making me restless

 

[jayanth.devarayanadurga]

If your are connecting your uCs UART to PC then on the PC side you need a piece of software which allows PC UART to communicate with external hardware. This software is called device driver. To write a USART device driver you need to know the Serial Communication Protocol.

 

[FvM]

Also device drivers have levels. In case of doubt, both code parts can be called device drivers.