1. Example 18 Pulse Train Using Interrupts
Lecture L8.2

2. PIM_9DP256
Block Diagram
Timer module

3. Timer Pins
PT0 – PT7
Pins 9,10,11,12,
15,16,17,18

4. Timer Pins
PT0 – PT7
Pins 9,10,11,12,
15,16,17,18
PT6 = Pin 17

5. 16-bit free-running counter, TCNT
Pulse train
Output Compare
16-bit free-running counter, TCNT

7. MC9S12DP256B Interrupt Vectors

8. // Example 18: Interrupt-Driven Pulse Train
#include <hidef.h> /* common defines and macros */
#include <mc9s12dp256.h> /* derivative information */
#include "main_asm.h" /* interface to the assembly module */
#pragma LINK_INFO DERIVATIVE "mc9s12dp256b"
int period; // period of pulse train
int pwidth; // high pulse width of pulse train
// Timer channel 6 interrupt service routine
void interrupt 14 handler(){
ptrain6(period, pwidth); }
void main(void) {
PLL_init(); // set system clock frequency to 24 MHz
ptrain6_init();
period = 0x4567;
pwidth = 0x1234;
while(1) { // do nothing while generating pulse train