Do HW3

1 files changed, 94 insertions, 0 deletions

diff --git a/HW3.X/strap012_hw3prob2.c b/HW3.X/strap012_hw3prob2.c
new file mode 100644
index 0000000..4fad1cd
--- /dev/null
+++ b/HW3.X/strap012_hw3prob2.c
@@ -0,0 +1,94 @@
+#include <xc.h>
+
+// PIC24FJ64GA002 Configuration Bit Settings
+// 'C' source line config statements
+
+// CONFIG2
+#pragma config POSCMOD = NONE           // Primary Oscillator Select (Primary oscillator disabled)
+#pragma config I2C1SEL = PRI            // I2C1 Pin Location Select (Use default SCL1/SDA1 pins)
+#pragma config IOL1WAY = OFF            // IOLOCK Protection (IOLOCK may be changed via unlocking seq)
+#pragma config OSCIOFNC = OFF           // Primary Oscillator Output Function (OSC2/CLKO/RC15 functions as CLKO (FOSC/2))
+#pragma config FCKSM = CSECME           // Clock Switching and Monitor (Clock switching is enabled, Fail-Safe Clock Monitor is enabled)
+#pragma config FNOSC = FRCPLL           // Oscillator Select (Fast RC Oscillator with PLL module (FRCPLL))
+#pragma config SOSCSEL = SOSC           // Sec Oscillator Select (Default Secondary Oscillator (SOSC))
+#pragma config WUTSEL = LEG             // Wake-up timer Select (Legacy Wake-up Timer)
+#pragma config IESO = ON                // Internal External Switch Over Mode (IESO mode (Two-Speed Start-up) enabled)
+
+// CONFIG1
+#pragma config WDTPS = PS32768          // Watchdog Timer Postscaler (1:32,768)
+#pragma config FWPSA = PR128            // WDT Prescaler (Prescaler ratio of 1:128)
+#pragma config WINDIS = ON              // Watchdog Timer Window (Standard Watchdog Timer enabled,(Windowed-mode is disabled))
+#pragma config FWDTEN = OFF             // Watchdog Timer Enable (Watchdog Timer is disabled)
+#pragma config ICS = PGx1               // Comm Channel Select (Emulator EMUC1/EMUD1 pins are shared with PGC1/PGD1)
+#pragma config GWRP = OFF               // General Code Segment Write Protect (Writes to program memory are allowed)
+#pragma config GCP = OFF                // General Code Segment Code Protect (Code protection is disabled)
+#pragma config JTAGEN = OFF             // JTAG Port Enable (JTAG port is disabled)
+
+// This program measures the duty cycle (i.e., duration of a signal being 1) in
+// terms of num cycles.
+// INT0 pin has the external sig. T1 counts #cycles.
+// Both programmed as interrupts.
+
+volatile unsigned int overflow = 0;
+volatile unsigned long int numCycles = 0;  // duty cycle in terms of # TCY
+volatile unsigned int high = 0, low = 0;
+
+void __attribute__((__interrupt__,__auto_psv__)) _T1Interrupt(void)
+{
+    IFS0bits.T1IF = 0;
+    overflow++;
+}
+
+void __attribute__((__interrupt__,__auto_psv__)) _INT0Interrupt(void)
+{
+    _INT0IF = 0;
+
+    if (_INT0EP == 0){   // I was waiting for a rising edge
+        TMR1 = 0;
+        overflow = 0;
+    } else { // I was waiting for a falling edge
+        numCycles = TMR1 + 16000L * overflow;
+//        TMR1 = 0;         // uncomment these two lines if you want the period
+//        overflow = 0;     //       and not just active duty cycle. also
+                            //       delete the if part, and the last line
+                            //       that changes polarity of INT0EP
+    }
+
+    _INT0EP = 1 - _INT0EP;
+    
+}
+
+void setup(void)
+{
+    CLKDIVbits.RCDIV = 0; // make 16MHz
+    // setup INT0 (RB7) pin as input
+    AD1PCFG = 0x9fff;
+    LATBbits.LATB7 = 1;
+
+    T1CON = 0;
+    PR1 = 15999;
+    TMR1 = 0;
+    T1CONbits.TON = 1;
+
+    IFS0bits.T1IF = 0;
+    //IPC0bits.T1IP = 4;
+    /* enable Timer 1 interrupt */
+    IEC0bits.T1IE = 1;
+
+    _INT0EP = 0;
+    _INT0IF = 0;
+    _INT0IE = 1;
+
+}
+
+
+int main(void)
+{
+    unsigned long int count = 0;
+
+    setup();
+
+    while (1) {
+        count++;
+    }
+}