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5_3.c

/********************************************************************/
/*  Hochschule fuer Technik und Wirtschaft                          */
/*  Fakultät fuer Ingenieurwissenschaften                           */
/*  Labor fuer Eingebettete Systeme                                 */
/*  Mikroprozessortechnik                                           */
/********************************************************************/
/*                                                                  */
/*  C_Übung.C:                                                      */
/*	  Programmrumpf fuer C-Programme mit dem Keil                   */
/*    Entwicklungsprogramm uVision fuer ARM-Mikrocontroller         */
/*                                                                  */
/********************************************************************/
/*  Aufgaben-Nr.:        *                                          */
/*                       *                                          */
/********************************************************************/
/*  Gruppen-Nr.: 	       *                                          */
/*                       *                                          */
/********************************************************************/
/*  Name / Matrikel-Nr.: *  Matthias Riegler                        */
/*                       *                                          */
/*                       *                                          */
/********************************************************************/
/* 	Abgabedatum:         *                                          */
/*                       *                                          */
/********************************************************************/

#include <LPC21xx.H>		/* LPC21xx Definitionen    */



#define PCLOCK 12500000
#define BAUD 19200
#define FREQUENCY_DIVIDER (int)(PCLOCK/(BAUD*16))
#define UART0_PINSEL 0x05
#define UART_FIFO_TRANSMIT_MASK 0x20
#define UART_FIFO_RECEIVE_MASK 0x01
#define UART_FIFO 0x07 // 0b111
#define LCR_8BIT_1STOP_DLAB 0x83
#define DLAB_RESET 0x03

#define BYTE_HEXDUMP_COUNT 8
#define BYTE_4BIT_LSB 0x0F
#define BYTE_4BIT_MSB 0xF0
#define BYTE_4BIT_SHIFT 4

#define CR 0x0D
#define LF 0x0A

void transmitChar(char c);
char decToHex(unsigned char i);
unsigned char hexToDec(char c);
void* readAddr(void);
void hexDump(void* addr);

int main(void) {
	int i = 0;
	
	PINSEL0 |= UART0_PINSEL;
	U0LCR = LCR_8BIT_1STOP_DLAB;
	
	// Set Baudrate (LSB and MSB)
	U0DLL = FREQUENCY_DIVIDER % 256;
	U0DLM = FREQUENCY_DIVIDER / 256;
	
	// RESET DLAB Bit in order to enable access to other control registers
	U0LCR = DLAB_RESET;
	
	// Enable receive&transmit FIFO buffer
	U0FCR = UART_FIFO;
	
	// Print validate connection string
	for(;i < 10; i++) {
		transmitChar(decToHex(i));
	}
	for(;;) {
		hexDump(readAddr());
	}
}

void transmitChar(char c) {
	// send register ready?
	while((U0LSR & UART_FIFO_TRANSMIT_MASK) == 0);
	U0THR = c;
}

char readChar() {
	// receive register ready?
	while((U0LSR & UART_FIFO_RECEIVE_MASK) == 0);
	return U0THR;
}

char decToHex(unsigned char i) {
  // Single digit
	if (i < 10) {
		return '0' + i;
	}
	// A-F
	return 'A' + (i-10);
}

unsigned char hexToDec(char c) {
  // Single digit
	if (c < 'A') {
		return c - '0';
	}
	// A-F
	return c - 'A';	
}

void* readAddr(void) {
	int i = 0;
	char currChar = ' ';
	unsigned long addr = 0;
	transmitChar(CR);
	transmitChar(LF);
	for(; i < 8; i++) {
		currChar = readChar();
		if (currChar == CR) break;
		// Update address
		addr = hexToDec(currChar) | addr << 4;
		// Echo input
		transmitChar(currChar);
	}
	return (void*) addr;
}

void hexDump(void* addr) {
	int i = 0;
	// cast address to an unsigned char at that position
	unsigned char *pc = (unsigned char*) addr;
	// temp value
	unsigned char toDump = 0x00;
	
	transmitChar(':');

	for(;i < 8; i++) {
		transmitChar(' ');	
		toDump = *(pc + i);
		
		// hexdump of one byte
		transmitChar(decToHex((toDump & BYTE_4BIT_MSB) >> BYTE_4BIT_SHIFT));
		transmitChar(decToHex(toDump & BYTE_4BIT_LSB));
	}
}