main.c

@@ -0,0 +1,128 @@
+#include<stdint.h>
+#include<stdbool.h>
+#include"tm4c123gh6pm.h"
+
+#define SW_bits 0x11
+#define RED 0x02
+#define BLUE 0x04
+#define GREEN 0x08
+
+
+/* Systick memory mapped registers */
+#define STCTRL *((volatile long *) 0xE000E010)      // control and status
+#define STRELOAD *((volatile long *) 0xE000E014)    // reload value
+#define STCURRENT *((volatile long *) 0xE000E018)   // current value
+#define ENABLE      (1 << 0)    // bit 0 of CSR to enable the timer
+#define CLKINT      (1 << 2)    // bit 2 of CSR to specify CPU clock
+#define SYS_INTEN      (1 << 1)    // enable systick interrupt
+
+void UART_INIT()
+{
+    SYSCTL_RCGCGPIO_R |= 0x30;             // Enabling clock to Port E and Port F
+    SYSCTL_RCGCUART_R |= (1<<7)|(1<<5);    // Enabling clock to UART 5th and 7th module
+    GPIO_PORTE_LOCK_R = 0x4C4F434B;        // Unlocking commit registers
+    GPIO_PORTE_CR_R |= 0xFF;               // commit register
+    /* configuring PORT E pins as Alternate function selection register */
+    GPIO_PORTE_AFSEL_R |= 0x33;            // configuring Port E 0 1 4 5 pins as alternate function
+    GPIO_PORTE_PCTL_R |= (1<<20)|(1<<16)|(1<<4)|(1<<0);
+    GPIO_PORTE_DIR_R = 0x33;               // setting PE5 and PE1 as output and PE4 and PE1 as input
+    GPIO_PORTE_DEN_R |= 0x33;              // setting  digital pins
+
+    // configuring UART 5 th module
+    UART5_CTL_R &= ~(0x01);                // disabling uart 5 module
+    UART5_IBRD_R =104;        // setting the baud rate as 9600
+    UART5_FBRD_R = 11;        // setting baud rate as 9600
+    UART5_LCRH_R =0x62;
+    UART5_CC_R = 0;
+    UART5_CTL_R |= ((1<<0)|(1<<8)|(1<<9));
+
+    /* Configuring NVIC and interrupt for uart module 5*/
+    /* UART5 has number 61 assigned for the interrupt vector table*/
+    UART5_IM_R &= ((0<<4)|(0<<5)|(0<<8));       //Mask Tx, Rx and Parity interrupts
+    UART5_ICR_R &= ((0<<4)|(0<<5)|(0<<8));      //Clear Tx, Rx and Parity interrupts
+    UART5_IM_R |= (1<<4);                       //Enable Rx interrupt
+    NVIC_EN1_R |= (1<<29);                      //Interrupts enabled for UART5
+    NVIC_PRI15_R &= 0xFFFF5FFF;                 //Interrupt Priority 2 to UART5
+}
+
+void GPIO_INIT()
+{
+    // here we will configure the GPIO pins.
+    /* switch 1 is connected to PF4 and switch 2 is connected to PF0 */
+    GPIO_PORTF_LOCK_R = 0x4C4F434B;     //Unlock PortF register
+    GPIO_PORTF_CR_R = 0x1F;             //Enable Commit function
+    GPIO_PORTF_DIR_R = 0x0E;     // setting PF0  and PF4 as input pins
+    GPIO_PORTF_DEN_R = 0x1F;     // digital enabling the pins.
+    GPIO_PORTF_PUR_R = 0x11;     // enabling pullup resistors
+
+    // configuring for interrupt
+    GPIO_PORTF_IS_R &= ~SW_bits;        //Edge trigger detected
+    GPIO_PORTF_IBE_R &= ~SW_bits;       //Trigger interrupt according to GPIOIEV
+    GPIO_PORTF_IEV_R &= ~SW_bits;       //Trigger interrupt on falling edge
+    GPIO_PORTF_IM_R &= ~SW_bits;        //Mask interrupt bits
+    GPIO_PORTF_ICR_R |= SW_bits;        //clear any prior interrupts
+    GPIO_PORTF_IM_R |= SW_bits;         //enable interrupts for bits corresponding to Mask_Bits
+    // setting priorities using NVIC
+    NVIC_EN0_R |=(1<<30);
+    NVIC_PRI7_R &= 0xFF3FFFFF;
+
+
+}
+
+void GPIO_Intrpt_HANDLER()
+{
+    int x;
+    x=GPIO_PORTF_MIS_R;
+    GPIO_PORTF_IM_R &= ~SW_bits;//sw1 and sw2 masked
+
+    /* pressing Switch 1 -> Send AA
+     * pressing Switch 2 -> Send F0*/
+
+    if(x & 0X10) //interrupt on switch 1
+    {
+        UART5_DR_R = 0xF0;
+
+    }
+    if(x & 0X01) // Interrupt on switch 2
+    {
+        UART5_DR_R = 0xAA;
+    }
+
+
+    //GPIO_PORTF_IM_R |= SW_bits;    // unmasking sw1 and sw2
+
+
+}
+void UART_Intrpt_HANDLER()
+{   UART5_IM_R &= (0<<4);       //Mask UART Rx interrupt
+    if(UART5_FR_R & (1<<6))
+    {
+        if(UART5_DR_R == 0xAA)
+            GPIO_PORTF_DATA_R = GREEN;
+        if(UART5_DR_R == 0XF0)
+            GPIO_PORTF_DATA_R = BLUE;
+    }
+
+        if(UART5_RSR_R & 0x0F)
+            GPIO_PORTF_DATA_R = RED;
+    UART5_ECR_R &= 0xFFFFFFF0;        //Clear UART errors
+    STRELOAD = 1000000*8;                  // for delay of 0.5 sec
+    STCURRENT = 0;
+    STCTRL |= (CLKINT | ENABLE | SYS_INTEN);    // set internal clock, enable the timer,enable interrupt
+    GPIO_PORTF_ICR_R |= SW_bits;   // clearing the interrupt
+}
+
+void SYSTICK_HANDLER()
+{
+    GPIO_PORTF_DATA_R  = 0x00;            // turn off LED LED
+    GPIO_PORTF_ICR_R = SW_bits;         // clear interrupt for port F
+    GPIO_PORTF_IM_R |= SW_bits;        // unmask interrupts for sw1 and sw2
+    UART5_IM_R |= (1<<4);
+}
+
+void main()
+{
+    UART_INIT();
+    GPIO_INIT();
+    while(1){}
+}