A Small Multi-Tasking Operation System Using 8051: uart.c Source File

00001 /**************************************************
00002 * Uart driver
00003 * Function: Driver for 8051 uart interface  
00004 *           
00005 * File:    uart.c
00006 * Author:  Book Chen
00007 * 2008.08.08 
00008 ****************************************************
00009 */
00010 #include "..\inc\includes.h"
00011 
00012 struct UART_CONTROL UartCtrl; 
00013 bit bUartTransfer;
00014 
00015 void  F_UartPowerOnInit(void) LargeReentrant;
00016 void  F_UartSvc(void) LargeReentrant;
00017 void  F_UartKeyInPut(INT8U KeyCode) LargeReentrant;
00018 INT8U F_UartKeyInGet() LargeReentrant;
00019 INT8U F_UartCheckKeyInBuffer() LargeReentrant;
00020 void  F_UartKeyOutPut(INT8U) LargeReentrant;
00021 INT8U F_UartKeyOutGet() LargeReentrant;
00022 INT8U F_UartKeyOutGetIsr() LargeReentrant;
00023 INT8U F_UartCheckKeyOutBuffer() LargeReentrant;
00024 INT8U F_UartCheckKeyOutBufferIsr() LargeReentrant;
00025 char  putchar(char) LargeReentrant;
00026 char  getchar(void) LargeReentrant;
00027 
00028 void F_UartPowerOnInit(void) LargeReentrant{
00029     // Initial UART H/W
00030     SCON|=0x50;        // serial configuration register...
00031                        // bit76=01 mode 1 8 bit uart,bit4=1 receive enable.
00032     ES=1;              // Enable serial interrupt...interrupt 4
00033     // variable initial    
00034     bUartTransfer=0;
00035     UartCtrl.KeyInGet=0;
00036     UartCtrl.KeyInPut=0; 
00037 }
00038 void F_UartKeyInPut(INT8U KeyCode) LargeReentrant{
00039     if(UartCtrl.KeyInPut<(KEY_IN_BUFFER_SIZE-1)){
00040         if((UartCtrl.KeyInPut+1)!=UartCtrl.KeyInGet){
00041             UartCtrl.KeyInPut++;
00042             UartCtrl.KeyInBuffer[UartCtrl.KeyInPut]=KeyCode;
00043         }
00044     }
00045     else{
00046         if(UartCtrl.KeyInGet==0);
00047         else{
00048             UartCtrl.KeyInPut=0;
00049             UartCtrl.KeyInBuffer[UartCtrl.KeyInPut]=KeyCode;
00050         } 
00051     }
00052 }
00053 INT8U F_UartKeyInGet(void) LargeReentrant{
00054     if(UartCtrl.KeyInGet!=UartCtrl.KeyInPut){
00055         if(UartCtrl.KeyInGet<(KEY_IN_BUFFER_SIZE-1)){
00056             UartCtrl.KeyInGet++;
00057             return UartCtrl.KeyInBuffer[UartCtrl.KeyInGet];      
00058         }
00059         else{         
00060             UartCtrl.KeyInGet=0;
00061             return UartCtrl.KeyInBuffer[UartCtrl.KeyInGet];
00062         }
00063     }
00064     return 0xff;
00065 }
00066 INT8U F_UartCheckKeyInBuffer(void) LargeReentrant{  // check key in buffer status
00067     if(UartCtrl.KeyInPut<(KEY_IN_BUFFER_SIZE-1)){
00068         if((UartCtrl.KeyInPut+1)==UartCtrl.KeyInGet) return UART_KEY_BUFFER_FULL;       
00069         else if(UartCtrl.KeyInGet!=UartCtrl.KeyInPut) return UART_KEY_BUFFER_NOT_FULL;        
00070         else return UART_KEY_BUFFER_EMPTY;                                      
00071     }
00072     else{
00073         if(UartCtrl.KeyInGet==0) return UART_KEY_BUFFER_FULL;                        
00074         else if(UartCtrl.KeyInGet!=UartCtrl.KeyInPut) return UART_KEY_BUFFER_NOT_FULL;    
00075         else if(UartCtrl.KeyInGet==(KEY_IN_BUFFER_SIZE-1)) return UART_KEY_BUFFER_EMPTY;   
00076     }
00077 }
00078 char putchar(char c) LargeReentrant{ 
00079     while(bUartTransfer==1);                        
00080     if(c==0x0a){
00081         SBUF=0x0d;
00082         bUartTransfer=1;
00083         while(bUartTransfer==1);   
00084     }
00085     SBUF=c;
00086     bUartTransfer=1;
00087     while(bUartTransfer==1);   
00088     return c;
00089 }
00090 char getchar(void) LargeReentrant{                         
00091     while(F_UartCheckKeyInBuffer()==UART_KEY_BUFFER_EMPTY);  
00092     return (F_UartKeyInGet());
00093 }
00094 
00095 
00096 
00097