pic 8880 8870 8880 dtmf
iampic:
It's a 4bit BCD output, and the STD pin that informs you with a logic high level, that a DTMF tone was detected. Why do you need a driver ???
2 possibilities:
first: poll STD pin until you get a logical 1, this means a tone was received
second: put STD on a interrupt pin, if the interrupt occur, a tone was received
In both scenarios look for the BCD output, this will give you the information which tone was received.
Simple ... isn't it???
Greetings