hellow everyone
i want to read the Dtmf. i used the MT8880 for recieving & transmiting the dtmf.The irq of MT8880 is connected to the INT0.but irq of MT8880 goes low by lowing the 8051 interrup0.
there might be the intialization problem.even i tried my best to do the intialization accurate.
In cotroll RegisterA : b1 = 0, b2= 1 & b3 = 1;
In controll redister B: b0 = 1.
i also enable the External interrupt as.
EX0 = 1; IT0 = 1; EA= 1.
please help me . thank you.