uartintc.pic18.ex.txt

Microchip PIC18F 设备驱动 UART 部分

/*********************************************************************
 * TITLE - USART library module for 'C' programming language.
 * FileName:        UARTIntC.PIC18.ex.ext
 * Version:			1.0
 * Overview:
 * The following main() program demonstrates use of library module. 
 * There are various test cases, which are grouped together by 
 * comments. User can uncomment only one test case at a time and run 
 * the application and see the results. There are lot of freeware and
 * shareware utilities which deal with serial port are avaialable. 
 * They can be used to monitor the data.

 * Author               Date        Comment
 *~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 * Reddy TE	  Sept. 19,2003	     Original Release
 * 
 * Reddy TE	  Sept. 24,2003	     Changed return values of func-
 *				     tions to unsigned char
 *
 ********************************************************************/
#include "UARTIntC.h"
#include "delays.h"

#include <p18f452.h>


void low_isr(void);

// serial interrupt taken as low priority interrupt
#pragma code uart_int_service = 0x08
void uart_int_service(void)
{
	_asm	goto low_isr	_endasm
	
}
#pragma code

#pragma	interruptlow low_isr save=section(".tmpdata")
void low_isr(void)
{	
	// call of library module function, MUST
	UARTIntISR();
}

void main(void)
{
	// Test data array
	unsigned char cArray[10]
	   = { 'A','B', 'C', 'D', 'E', 'F', 'G','H','I' , 'J'};
	
	// temporary local array	   
	unsigned char writtenArray[10];
	
	// local variables for all test cases and their initialisation
	unsigned char chData;
	unsigned char *pReadArray;
	unsigned char *pWriteArray;
	unsigned char j = 0;
	unsigned char i  = 0;
	unsigned char l = 0;
	unsigned char k = 0;			
	pReadArray = pWriteArray = writtenArray;	


	// call of library module , MUST
	UARTIntInit();	


// TEST 1
// Sending Test array data, 100 times, from micro-controller to PC
// and waiting infinitely at the end.

   for(j = 0; j < 100; j++)
	{
		k = 0;
		while(k < 10)
		{
			if(UARTIntPutChar(cArray[k]))
				 k++;			
		}		   
	}	
	while(1);


// TEST 2
// Similar to TEST1
	/*
	
	for(j = 0; j < 100; j++)
	{
		k = 0;
		while(k < 10)
		{  
			if(!vUARTIntStatus.UARTIntTxBufferFull)
			 UARTIntPutChar(cArray[k++]);
		}		   
	}	
	while(1);
	
	*/


// TEST 3
//	Sending Test array data, continuously, from micro-controller to PC
//  Usage of status flag can be seen in below example
	/*
	
	while(1)  
	{
		i = 0;
		while(i<10)
		{   //status flag
			if(!vUARTIntStatus.UARTIntTxBufferFull)
			{
				 UARTIntPutChar(cArray[i]);		
				 i++;
			 }
		 }		
	}

	*/
	
//	TEST 4
//	Sending Test array data, continuously, from micro-controller to PC
// 	Usage of UARTIntGetTxBufferEmptySpace() function can be seen below
	/*
	
	while(1)
	{
		i = 0;
		while(i < 10) //works  change to pointer
		{   
			l = 0;
			l = UARTIntGetTxBufferEmptySpace();
			for(k = 0; k < l; k++)
			{   if((i+k) < 10)
				UARTIntPutChar(cArray[i+k]);			
			}
			i = i+ k;						
		}					
	}	

	*/


//	TEST 5
//  Checking transmission and reception simultaneously.
//  Sending Test array data, 100 times ,from micro-controller to PC.
//  During this transmission, a single character 'A' or 'B' or 'C' 
//  can be sent from PC to micro-controller. This can be seen as LED
//  glows on PICDEM2 board. At the end of transmission micro-controller
//  waits infinitely at the end.
	/*		
  
  	TRISB = 0;
	PORTB = 0;
    k = 0;

	while(k < 100)
	{
		for(j = 0; j < 100; j++)
		{
			i = 0;
			do{
				if(vUARTIntStatus.UARTIntTxBufferEmpty)
					UARTIntPutChar(cArray[i++]);
			}while(i < 10);
		}
		
		if( !(vUARTIntStatus.UARTIntRxError) && 
		    !(vUARTIntStatus.UARTIntRxOverFlow) &&
		    !(vUARTIntStatus.UARTIntRxBufferEmpty))
		{    
			if(UARTIntGetChar(&chData))
			PORTB = chData;
		}
		
		k++;
	}
	
	while(1);			

	*/


//	TEST 6
//  Chunk of 30 characters can be sent from PC to micro-controller.
//  Each received character at micro-controller is read and immediately 
//	sent back to PC.
	/*
	
	while(1)
	{
		while(!vUARTIntStatus.UARTIntRxBufferEmpty)
		{
			UARTIntGetChar(&chData);			
			if(!vUARTIntStatus.UARTIntTxBufferFull)
				UARTIntPutChar(chData);
		};
	};

	*/


//	TEST 7
// 	Chunk of data is sent from PC to micro. Data received at micro is
//	read in to temporary buffer. The data is immediately sent back to 
//  PC. Usage of pointers is displayed in below example
	/*
	
	while(1)   
	{		   
		l = 0;
		l = UARTIntGetRxBufferDataSize();	
		while(l > 0)
		{
			if(UARTIntGetChar(pWriteArray))
			{				
				if(!vUARTIntStatus.UARTIntTxBufferFull)
				    UARTIntPutChar(*pWriteArray);
				l--; pWriteArray++;
				if(pWriteArray == (writtenArray + 10))
					pWriteArray = writtenArray;
			}
		}
	}
		
	*/
	

//	TEST 8
// 	Chunk of data is sent from PC to micro. Data received at micro is
//	read in to temporary buffer. The data is sent back to PC. Here 
//  reception and transmission is done independently.
	/*
	
	
	while(1)   
	{					   
		l = 0;
		l = UARTIntGetRxBufferDataSize();	
		while(l > 0)
		{
			if(UARTIntGetChar(pReadArray))
			{				
				l--; pReadArray++;
				if(pReadArray == (writtenArray + 10))
					pReadArray = writtenArray;
			}
		}		
		if((pWriteArray < pReadArray) || ((pWriteArray - pReadArray) == 9 ))
		{  
			if(!vUARTIntStatus.UARTIntTxBufferFull)
			{
				UARTIntPutChar(*pWriteArray);
	    		i--; pWriteArray++;
 			    if(pWriteArray == (writtenArray + 10))				  			
					pWriteArray = writtenArray;		
			}
		}									
	}
	
	*/
	
	
}