USING CCS PROGRAMMING PLEASE EXPLAIN LINE BY WHAT THE CODE IS DOING

#include

#include

#include

#include //Exact-width integer types

#include //Driver library

#define DCO_FREQ 48e6 //unit: Hz; DCO nominal frequencies: 1.5, 3, 6, 12, 24,

48 MHz.

#define TIMER0_FREQ 1 //unit: Hz

#define RED_LED GPIO_PIN0

#define GREEN_LED GPIO_PIN1

#define BLUE_LED GPIO_PIN2

#define NUM_DISP_TEXT_LINE 4

#define MAX_STR_BUFFER_LEN 100

//Function prototypes

void initDevice(void);

void initGPIO(void);

void initTimer(void);

void initUART(void);

void initADC14(void);

void uart0_transmitStr(const char *str);

//Global variables

uint32_t clockMCLK;

uint8_t currentLED = RED_LED;

volatile uint32_t tempSensorCal30, tempSensorCal85, tempSensorCalDiff;

char strBuffer[MAX_STR_BUFFER_LEN];

const char *terminalDisplayText[NUM_DISP_TEXT_LINE] =

{

" ",

"UART and User Button Demo ",

"R: Red, G: Green, B: Blue, S: Sample, H: Help ",

"> "

};

void main(void)

{

uint32_t i;

uint8_t data;

initDevice();

initGPIO();

initTimer();

initUART();

initADC14();

Interrupt_enableMaster();

Timer32_startTimer(TIMER32_0_BASE, false);

//Initial display on terminal.

for(i=0; i

{

uart0_transmitStr(terminalDisplayText[i]);

}

while(1)

{

if(UART_getInterruptStatus(EUSCI_A0_BASE,

EUSCI_A_UART_RECEIVE_INTERRUPT_FLAG))

{

data = UART_receiveData(EUSCI_A0_BASE);

UART_clearInterruptFlag(EUSCI_A0_BASE,

EUSCI_A_UART_RECEIVE_INTERRUPT_FLAG);

switch(data)

{

case 'R':

case 'r':

currentLED = RED_LED;

uart0_transmitStr("Blink red LED. > ");

break;

case 'G':

case 'g':

currentLED = GREEN_LED;

uart0_transmitStr("Blink green LED. > ");

break;

case 'B':

case 'b':

currentLED = BLUE_LED;

uart0_transmitStr("Blink blue LED. > ");

break;

case 'H':

case 'h':

for(i=0; i

{

uart0_transmitStr(terminalDisplayText[i]);

}

break;

case 'S':

case 's':

ADC14_toggleConversionTrigger();

break;

}

} //end of if

} //end of while

}

void initDevice(void)

{

WDT_A_holdTimer(); //Stop Watchdog timer

//Change VCORE to 1 to support a frequency higher than 24MHz.

//See data sheet for Flash wait-state requirement for a given frequency.

PCM_setPowerState(PCM_AM_LDO_VCORE1);

FlashCtl_setWaitState(FLASH_BANK0, 1);

FlashCtl_setWaitState(FLASH_BANK1, 1);

//Enable FPU for DCO Frequency calculation.

FPU_enableModule();

FPU_enableLazyStacking(); //Required to use FPU within ISR.

//Only use DCO nominal frequencies: 1.5, 3, 6, 12, 24, 48MHz.

CS_setDCOFrequency(DCO_FREQ);

//Divider: 1, 2, 4, 8, 16, 32, 64, or 128.

//SMCLK used by UART and ADC14.

CS_initClockSignal(CS_MCLK, CS_DCOCLK_SELECT, CS_CLOCK_DIVIDER_1);

CS_initClockSignal(CS_HSMCLK, CS_DCOCLK_SELECT, CS_CLOCK_DIVIDER_8);

CS_initClockSignal(CS_SMCLK, CS_DCOCLK_SELECT, CS_CLOCK_DIVIDER_16);

clockMCLK = CS_getMCLK();

}

void initGPIO(void)

{

//Configure P2.0, P2.1, P2.2 as output.

//P2.0, P2.1, P2.2 are connected to a RGB tri-color LED on LaunchPad.

GPIO_setAsOutputPin(GPIO_PORT_P2, GPIO_PIN0|GPIO_PIN1|GPIO_PIN2);

}

void initTimer(void)

{

Timer32_initModule(TIMER32_0_BASE, TIMER32_PRESCALER_1, TIMER32_32BIT,

TIMER32_PERIODIC_MODE);

Timer32_setCount(TIMER32_0_BASE, clockMCLK/TIMER0_FREQ);

Timer32_enableInterrupt(TIMER32_0_BASE);

Interrupt_enableInterrupt(INT_T32_INT1); //Enable Timer32_0 interrupt in the

interrupt controller.

}

void initUART(void)

{

//Configuration for 3MHz SMCLK, 9600 baud rate.

//Calculated using the online calculator that TI provides at:

//http://software-dl.ti.com/msp430/msp430_public_sw/mcu/msp430/MSP430BaudRateConver

ter/index.html

const eUSCI_UART_Config config =

{

EUSCI_A_UART_CLOCKSOURCE_SMCLK, // SMCLK Clock Source

19, //BRDIV = 19

8, //UCxBRF = 8

0, //UCxBRS = 0

EUSCI_A_UART_NO_PARITY, //No Parity

EUSCI_A_UART_LSB_FIRST, //MSB First

EUSCI_A_UART_ONE_STOP_BIT, //One stop bit

EUSCI_A_UART_MODE, //UART mode

EUSCI_A_UART_OVERSAMPLING_BAUDRATE_GENERATION // Oversampling

};

//Configure GPIO pins for UART. RX: P1.2, TX:P1.3.

GPIO_setAsPeripheralModuleFunctionInputPin(GPIO_PORT_P1, GPIO_PIN2 | GPIO_PIN3,

GPIO_PRIMARY_MODULE_FUNCTION);

UART_initModule(EUSCI_A0_BASE, &config);

UART_enableModule(EUSCI_A0_BASE);

}

//Use A22 to sample internal temperature sensor

void initADC14(void)

{

ADC14_enableModule();

ADC14_initModule(ADC_CLOCKSOURCE_SMCLK, ADC_PREDIVIDER_1, ADC_DIVIDER_1,

ADC_TEMPSENSEMAP);

ADC14_configureSingleSampleMode(ADC_MEM0, false);

ADC14_configureConversionMemory(ADC_MEM0, ADC_VREFPOS_INTBUF_VREFNEG_VSS,

ADC_INPUT_A22, false);

//See TechRef Section 20.2.6 for sample timing consideration.

ADC14_enableSampleTimer(ADC_MANUAL_ITERATION);

ADC14_setSampleHoldTime(ADC_PULSE_WIDTH_4, ADC_PULSE_WIDTH_4);

ADC14_enableConversion();

ADC14_enableInterrupt(ADC_INT0); //Interrupt for ADC_MEM0

Interrupt_enableInterrupt(INT_ADC14);

//Set VREF to 2.5 and enable internal temperature sensor.

REF_A_enableTempSensor();

REF_A_setReferenceVoltage(REF_A_VREF2_5V);

REF_A_enableReferenceVoltage();

//Get temperature sensor calibration data.

tempSensorCal30 = SysCtl_getTempCalibrationConstant(SYSCTL_2_5V_REF,

SYSCTL_30_DEGREES_C);

tempSensorCal85 = SysCtl_getTempCalibrationConstant(SYSCTL_2_5V_REF,

SYSCTL_85_DEGREES_C);

tempSensorCalDiff = tempSensorCal85 - tempSensorCal30;

}

//Transmit a string through UART0.

void uart0_transmitStr(const char *str)

{

uint32_t len, i=0;

len = strlen(str);

while(i < len)

{

UART_transmitData(EUSCI_A0_BASE, str[i++]);

while(!UART_getInterruptStatus(EUSCI_A0_BASE,

EUSCI_A_UART_TRANSMIT_COMPLETE_INTERRUPT_FLAG));

UART_clearInterruptFlag(EUSCI_A0_BASE,

EUSCI_A_UART_TRANSMIT_COMPLETE_INTERRUPT_FLAG);

}

}

//Timer32_0 ISR

void T32_INT1_IRQHandler(void)

{

Timer32_clearInterruptFlag(TIMER32_0_BASE);

if(GPIO_getInputPinValue(GPIO_PORT_P2, GPIO_PIN0|GPIO_PIN1|GPIO_PIN2))

GPIO_setOutputLowOnPin(GPIO_PORT_P2, GPIO_PIN0|GPIO_PIN1|GPIO_PIN2);

else

GPIO_setOutputHighOnPin(GPIO_PORT_P2, currentLED);

}

void ADC14_IRQHandler(void)

{

uint64_t status;

float data, tempC, tempF;

status = ADC14_getEnabledInterruptStatus();

ADC14_clearInterruptFlag(status);

if(status & ADC_INT0)

{

data = ADC14_getResult(ADC_MEM0);

data = (data - tempSensorCal30)*55;

tempC = (data/tempSensorCalDiff) + 30;

tempF = tempC*9/5 + 32;

snprintf(strBuffer, MAX_STR_BUFFER_LEN, "tempC = %.1f, tempF = %.1f > ",

tempC, tempF);

uart0_transmitStr(strBuffer);

}

}