exercise1_lab2

// Copyright by Adam Kinsman, Henry Ko and Nicola Nicolici
// Developed for the Embedded Systems course (COE4DS4)
// Department of Electrical and Computer Engineering
// McMaster University
// Ontario, Canada

#include "io.h"
#include "system.h"
#include "alt_types.h"
#include "sys/alt_stdio.h"
//#include <stdio.h>

alt_u16 disp_seven_seg(alt_u8 val) {
    switch (val) {
        case  0 : return 0x40;
        case  1 : return 0x79;
        case  2 : return 0x24;
        case  3 : return 0x30;
        case  4 : return 0x19;
        case  5 : return 0x12;
        case  6 : return 0x02;
        case  7 : return 0x78;
        case  8 : return 0x00;
        case  9 : return 0x18;
        case 10 : return 0x08;
        case 11 : return 0x03;
        case 12 : return 0x46;
        case 13 : return 0x21;
        case 14 : return 0x06;
        case 15 : return 0x0e;
        default : return 0x7f;
    }
}

int main()
{
    alt_8 i;
    alt_8 j;
    alt_8 k;
    alt_u32 switch_val;
    alt_putstr("Experiment 2!\n");

    //j = 2;
   // alt_printf("%x", j);

    /* Event loop never exits. */
    while (1) {
        switch_val = IORD(SWITCH_I_BASE, 0);
        IOWR(LED_RED_O_BASE, 0, switch_val);
        if (switch_val == 0) {
            IOWR(SEVEN_SEGMENT_N_O_1_BASE, 0,
                disp_seven_seg(16));
            IOWR(SEVEN_SEGMENT_N_O_0_BASE, 0,
                disp_seven_seg(16));
        } else {

    // THIS IS FIRST PART

            for (i = 17; i >= 0; i--) {
                if (((switch_val >> i) & 0x1) != 0){
                    j = j+1;
                }
            //  alt_printf("%x", j);
            }
            if(j >= 9){
                // THIS IS THE SECOND PART INSIDE THE FIRST PART

                         // IF SWITCH 17 IS ON AND AT LEAST ONE OTHER SWITCH IS LOW,
                         // THEN DISPLAY BINARY OF MOST SIGNIFICANT SWITCH THAT IS LOW
                            if((switch_val >= 0x20000) && (switch_val < 0x3FFFF)){
                                for (k = 16; k >= 0; k--) {
                                    if (((switch_val >> k) & 0x1) == 0) {
                                        IOWR(LED_GREEN_O_BASE, 0, 224+k);
                                        k = 0;
                                    }
                                }
                            }
                         // IF SWITCH 17 IS LOW AND SWITCH 16 IS HIGH THEN DISPLAY
                         // BINARY OF LEAST SIGNIFICANT SWITCH THAT IS LOW
                            else if((switch_val >= 0x10000) && (switch_val < 0x20000)){
                                for (k = 0; k <= 15; k++) {
                                    if (((switch_val >> k) & 0x1) == 0) {
                                        IOWR(LED_GREEN_O_BASE, 0, 224+k);
                                        k = 15;
                                    }
                                }
                            }
                         // IF ALL SWITCHES ARE ON THEN ALL GREEN LED'S ARE ON
                            else if(switch_val == 0x3FFFF){
                                IOWR(LED_GREEN_O_BASE, 0, 255);
                            }
                         // IF SWITCH 17 AND 16 ARE BOTH LOW THEN DISPLAY BINARY
                         // OF THE NUMBER OF SWITCHES THAT ARE HIGH
                            else if(switch_val <= 0xFFFF){
                                IOWR(LED_GREEN_O_BASE, 0, 224+j);
                            }
                            else {
                                IOWR(LED_GREEN_O_BASE, 0, 224);
                            }
            }
//------------------------------------------------------------------------------------------------------------------------
    // THIS IS THE SECOND PART

         // IF SWITCH 17 IS ON AND AT LEAST ONE OTHER SWITCH IS LOW,
         // THEN DISPLAY BINARY OF MOST SIGNIFICANT SWITCH THAT IS LOW
            else if(switch_val >= 0x20000){
                for (k = 16; k >= 0; k--) {
                    if (((switch_val >> k) & 0x1) == 0) {
                        IOWR(LED_GREEN_O_BASE, 0, k);
                        k = 0;
                    }
                }
            }
         // IF SWITCH 17 IS LOW AND SWITCH 16 IS HIGH THEN DISPLAY
         // BINARY OF LEAST SIGNIFICANT SWITCH THAT IS LOW
            else if((switch_val >= 0x10000) && (switch_val < 0x20000)){
                for (k = 0; k <= 15; k++) {
                    if (((switch_val >> k) & 0x1) == 0) {
                        IOWR(LED_GREEN_O_BASE, 0, k);
                        k = 15;
                    }
                }
            }
         // IF ALL SWITCHES ARE ON THEN ALL GREEN LED'S ARE ON
            else if(switch_val == 0x3FFFF){
                IOWR(LED_GREEN_O_BASE, 0, 255);
            }
         // IF SWITCH 17 AND 16 ARE BOTH LOW THEN DISPLAY BINARY
         // OF THE NUMBER OF SWITCHES THAT ARE HIGH
            else if(switch_val <= 0xFFFF){
                IOWR(LED_GREEN_O_BASE, 0, j);
            }
            else {
                IOWR(LED_GREEN_O_BASE, 0, 0);
            }
            j = 0;
        }
    }

    return 0;
}