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Question 9.25: A switch is connected to pin P1.2. Write an 8051 C program t...

A switch is connected to pin P1.2. Write an 8051 C program to monitor SW and create the following frequencies on pin P1.7:
SW=0: 500Hz
SW=1: 750Hz, use Timer 0, mode 1 for both of them.

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#include <reg51.h>
sbit   mybit=P1^5;
sbit   SW=P1^7;
void  T0M1Delay(unsigned char);
void  main(void){

SW=1;
while (1) {

mybit=~mybit;
if (SW==0)

T0M1Delay(0);

else

T0M1Delay(1);

}

}
. . . . .
. . . . .
void T0M1Delay(unsigned char c){

TMOD=0x01;
if (c==0) {

TL0=0x67;
TH0=0xFC;^{\nearrow ^{\fbox{FC67H = 64615 65536 – 64615 = 921 921 × 1.085 μs = 999.285 μs 1 / (999.285 μs × 2) = 500 Hz } } }

}
else {

TL0=0x9A;
TH0=0xFD;

}
TR0=1;
while (TF0==0);
TR0=0;
TF0=0;

}

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