C51 COMPILER V8.08   PC_O                                                                  06/30/2007 15:58:44 PAGE 1   


C51 COMPILER V8.08, COMPILATION OF MODULE PC_O
OBJECT MODULE PLACED IN PC_O.OBJ
COMPILER INVOKED BY: C:\Keil\C51\BIN\C51.EXE PC_O.c BROWSE DEBUG OBJECTEXTEND

line level    source

   1          /*------------------------------------------------------------------*-
   2          
   3             PC_O.C (v1.01)
   4          
   5            ------------------------------------------------------------------
   6          
   7             Core files for simple write-only PC link library for 8051 family
   8             [Sends data to PC - cannot receive data from PC]
   9          
  10             Uses the USART, and Pin 3.1 (Tx) 
  11          
  12             See text for details (Chapter 18).
  13          
  14          
  15             COPYRIGHT
  16             ---------
  17          
  18             This code is from the book:
  19          
  20             PATTERNS FOR TIME-TRIGGERED EMBEDDED SYSTEMS by Michael J. Pont 
  21             [Pearson Education, 2001; ISBN: 0-201-33138-1].
  22          
  23             This code is copyright (c) 2001 by Michael J. Pont.
  24           
  25             See book for copyright details and other information.
  26          
  27          -*------------------------------------------------------------------*/
  28          
  29          #include "Main.h"
  30          #include "PC_O.h"
  31          
  32          // ------ Public variable definitions ------------------------------
  33          
  34          tByte Out_written_index_G;  // Data in buffer that has been written 
  35          tByte Out_waiting_index_G;  // Data in buffer not yet written
  36          
  37          // ------ Public variable declarations -----------------------------
  38          
  39          // The error code variable
  40          //
  41          // See Main.H for port on which error codes are displayed
  42          // and for details of error codes
  43          extern tByte Error_code_G;
  44          
  45          // ------ Private constants ----------------------------------------
  46          
  47          // The transmit buffer length
  48          #define TRAN_BUFFER_LENGTH 20
  49          
  50          // ------ Private variables ----------------------------------------
  51          
  52          static tByte Tran_buffer[TRAN_BUFFER_LENGTH];
  53          
  54          /*------------------------------------------------------------------*-
  55          
C51 COMPILER V8.08   PC_O                                                                  06/30/2007 15:58:44 PAGE 2   

  56            PC_LINK_O_Update()
  57          
  58            Sends next character from the software transmit buffer
  59          
  60            NOTE: Output-only library (Cannot receive chars)
  61          
  62            Uses on-chip UART hardware.
  63          
  64          -*------------------------------------------------------------------*/
  65          void PC_LINK_O_Update(void)
  66             {
  67   1         // Deal with transmit bytes here
  68   1      
  69   1         // Is there any data ready to send?
  70   1         if (Out_written_index_G < Out_waiting_index_G)
  71   1            {
  72   2            PC_LINK_O_Send_Char(Tran_buffer[Out_written_index_G]);     
  73   2      
  74   2            Out_written_index_G++;
  75   2            }
  76   1         else
  77   1            {
  78   2            // No data to send - just reset the buffer index
  79   2            Out_waiting_index_G = 0;
  80   2            Out_written_index_G = 0;
  81   2            }
  82   1      
  83   1         }
  84          
  85          /*------------------------------------------------------------------*-
  86          
  87            PC_LINK_O_Write_String_To_Buffer()
  88          
  89            Copies a (null terminated) string to the character buffer.  
  90            (The contents of the buffer are then passed over the serial link)
  91          
  92          -*------------------------------------------------------------------*/
  93          void PC_LINK_O_Write_String_To_Buffer(const char* const STR_PTR)
  94             {
  95   1         tByte i = 0;
  96   1      
  97   1         while (STR_PTR[i] != '\0')
  98   1            {
  99   2            PC_LINK_O_Write_Char_To_Buffer(STR_PTR[i]);
 100   2            i++;
 101   2            }
 102   1         }
 103          
 104          /*------------------------------------------------------------------*-
 105          
 106            PC_LINK_O_Write_Char_To_Buffer()
 107          
 108            Stores a character in the 'write' buffer, ready for 
 109            later transmission
 110           
 111          -*------------------------------------------------------------------*/
 112          void PC_LINK_O_Write_Char_To_Buffer(const char CHARACTER)
 113             {
 114   1         // Write to the buffer *only* if there is space
 115   1         if (Out_waiting_index_G < TRAN_BUFFER_LENGTH)
 116   1            {
 117   2            Tran_buffer[Out_waiting_index_G] = CHARACTER;
C51 COMPILER V8.08   PC_O                                                                  06/30/2007 15:58:44 PAGE 3   

 118   2            Out_waiting_index_G++;     
 119   2            }
 120   1         else
 121   1            {
 122   2            // Write buffer is full
 123   2            // Increase the size of TRAN_BUFFER_LENGTH
 124   2            // or increase the rate at which UART 'update' function is called 
 125   2            // or reduce the amount of data sent to PC
 126   2            Error_code_G = ERROR_USART_WRITE_CHAR;
 127   2            }
 128   1         }
 129          
 130          /*------------------------------------------------------------------*-
 131          
 132            PC_LINK_O_Send_Char()
 133          
 134            Based on Keil sample code, with added (loop) timeouts.
 135            Implements Xon / Off control.
 136          
 137            Uses on-chip UART hardware.
 138          
 139          -*------------------------------------------------------------------*/
 140          void PC_LINK_O_Send_Char(const char CHARACTER)
 141             {
 142   1         tLong Timeout1 = 0;
 143   1      
 144   1         if (CHARACTER == '\n')  
 145   1            {
 146   2            Timeout1 = 0;
 147   2            while ((++Timeout1) && (TI == 0));  
 148   2      
 149   2            if (Timeout1 == 0)
 150   2               {
 151   3               // usart did not respond - error
 152   3               Error_code_G = ERROR_USART_TI;
 153   3               return;
 154   3               } 
 155   2      
 156   2            TI = 0;
 157   2            SBUF = 0x0d;  // output CR  
 158   2            }
 159   1        
 160   1         Timeout1 = 0;
 161   1         while ((++Timeout1) && (TI == 0));  
 162   1      
 163   1         if (Timeout1 == 0)
 164   1            {
 165   2            // usart did not respond - error
 166   2            Error_code_G = ERROR_USART_TI;
 167   2            return;
 168   2            } 
 169   1      
 170   1         TI = 0;
 171   1      
 172   1         SBUF = CHARACTER;
 173   1         }
 174          
 175          /*------------------------------------------------------------------*-
 176            ---- END OF FILE -------------------------------------------------
 177          -*------------------------------------------------------------------*/


C51 COMPILER V8.08   PC_O                                                                  06/30/2007 15:58:44 PAGE 4   

MODULE INFORMATION:   STATIC OVERLAYABLE
   CODE SIZE        =    199    ----
   CONSTANT SIZE    =   ----    ----
   XDATA SIZE       =   ----    ----
   PDATA SIZE       =   ----    ----
   DATA SIZE        =     22       9
   IDATA SIZE       =   ----    ----
   BIT SIZE         =   ----    ----
END OF MODULE INFORMATION.


C51 COMPILATION COMPLETE.  0 WARNING(S),  0 ERROR(S)