Problem: The following HCS12 program generates a square wave on pin PT0: (10 pts)

void main(void) {

// Set up timer

TSCR1 = 0x80; // Enable timer (TEN=1), no fast flag clear (TFFCA=0)

TSCR2 = 0x00; // No interrupts (TOI=0), prescale=000

5.

// Set up output compare on channel 0

TIOS = 0xff; // All Port T is output

TCTL2 = 0x01; // Configure PT0 to toggle

TIE = 0x01; // Enable interrupts on channel 0

TFLG1 = 0x01; // Clear any compare flag (C0F)

___asm CLI;

12.

for(;;) {

_FEED_COP();

}

}

17.

void interrupt (((0x10000-Vtimch7)/2-1) void TC0_ISR (void) {

TFLG1 = 0x01; // Clear compare flag (C0F)

TC0 = TC0 + 6000;

}

(a) Assuming a 24 MHz clock, what is the period of the square wave generated?

(b) Describe the output signal if the programmer used TC0 = TCNT + 6000; on line 20

(c) Describe the output signal if the programmer forgot to enable interrupts (the instruction on

line 9).