1. Example 5 Pushbutton Switches: S1 and S2
Lecture L3.1

2. miniDragon+
2 pushbutton switches
Serial cable
A/D Pot
I/O headers
Run/Load switch
Reset button
7-segment display
Power plug

4. Pushbutton Switches: S1 and S2
(PORTAD0 & 0x10) == 0
TRUE if S1 is closed
(PORTAD0 & 0x08) == 0
TRUE if S2 is closed

5. Example 5a // Example 5a: Pushbutton Switches
#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"
void main(void) {
PLL_init(); // set system clock frequency to 24 MHz
seg7_enable(); // enable 7-segment display
ATD0DIEN = 0x18; // enable S1 and S2
while(1){
if((PORTAD0 & 0x10) == 0)
seg7dec(1);
else
seg7_off();
if((PORTAD0 & 0x08) == 0)
seg7dec(2); }

6. Example 5b // Example 5b: Pushbutton Switches using C function calls
#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"
void main(void) {
PLL_init(); // set system clock frequency to 24 MHz
seg7_enable(); // enable 7-segment display
SW12_enable(); // enable S1 and S2
while(1){
if(SW1_down())
seg7dec(1);
else
seg7_off();
if(SW2_down())
seg7dec(2); }

7. Example 5

8. Example 5c // Example 5c: Pushbutton Switches - Problem 5.3
#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"
void main(void) {
PLL_init(); // set system clock frequency to 24 MHz
seg7_enable(); // enable 7-segment display
SW12_enable(); // enable S1 and S2
while(1){
while(SW1_down()){
seg7dec(1); }
seg7_off();
while(SW2_down()){
seg7dec(2);