C51 COMPILER V6.23a  TIMER                                                                 04/01/2003 10:13:08 PAGE 1   


C51 COMPILER V6.23a, COMPILATION OF MODULE TIMER
OBJECT MODULE PLACED IN Timer.OBJ
COMPILER INVOKED BY: C:\KEIL\C51\BIN\C51.EXE Timer.c DB OE

stmt level    source

   1          //-----------------------------------------------------------------------------
   2          // Copyright (c) 2002 Jim Brady
   3          // Do not use commercially without author's permission
   4          // Last revised August 2002
   5          // Net TIMER.C
   6          //
   7          // This module sets up the timer and handles the timer interrupt
   8          //-----------------------------------------------------------------------------
   9          #include "C8051f.h"
  10          #include "net.h"
  11          #include "timer.h"
  12          
  13          
  14          extern UINT volatile event_word;
  15          extern ULONG idata initial_sequence_nr;
  16          
  17          
  18          //--------------------------------------------------------------------------
  19          // Timer 2 interrupt service routing. Intr vector location is
  20          // address 0x002B. The timer generates an interrupt every 25 msec
  21          // It is set to auto reload so do not need to reload it.
  22          //--------------------------------------------------------------------------
  23          void timer2_interrupt(void) interrupt 5
  24          {
  25   1              static UINT count1 = 0;
  26   1              static UINT count2 = 0;
  27   1              
  28   1              TF2 = 0;                // Clear interrupt flag
  29   1      
  30   1              
  31   1              // Advance the initial sequence number
  32   1              initial_sequence_nr += 6250;
  33   1         // Keep it some distance from rolling over
  34   1         if (initial_sequence_nr & 0x10000000L) initial_sequence_nr = 1;
  35   1              
  36   1              count1++;
  37   1              // These events happens every 0.50 seconds, not simultaneously
  38   1              if (count1 == 5) event_word |= EVENT_ARP_RETRANSMIT;
  39   1              
  40   1              if (count1 == 10) event_word |= EVENT_TCP_INACTIVITY;
  41   1              
  42   1              if (count1 == 15) event_word |= EVENT_READ_ANALOG;
  43   1              
  44   1              if (count1 == 20)
  45   1              {
  46   2                      count1 = 0;
  47   2                      event_word |= EVENT_TCP_RETRANSMIT;
  48   2              }
  49   1              
  50   1              count2++;
  51   1              if (count2 == 2401)
  52   1              {
  53   2                      // This happens every 60.025 seconds, not simultaneous
  54   2                      // with above tasks
  55   2                      count2 = 0;
C51 COMPILER V6.23a  TIMER                                                                 04/01/2003 10:13:08 PAGE 2   

  56   2                      event_word |= EVENT_AGE_ARP_CACHE;
  57   2              }
  58   1      }
  59          
  60          
  61          
  62          
  63          
  64          //--------------------------------------------------------------------------
  65          // Setup Timer2 in mode 1 which is 16 bit auto reload
  66          // Intr rate = 22.1184 MHz /(12 * (65536 - reload value))
  67          // For 25 msec reload value = 19456 = 0x4C00
  68          //--------------------------------------------------------------------------
  69          void init_timer2(void)
  70          {
  71   1              T2CON = 0x00;
  72   1              RCAP2H = 0x4C;          // Reload value
  73   1              RCAP2L = 0x00;
  74   1              TH2 = 0x4C;                             // Initial load value
  75   1              TL2 = 0x00;
  76   1              TR2 = 1;                                        // Timer 2 run
  77   1      }
  78          
  79          


MODULE INFORMATION:   STATIC OVERLAYABLE
   CODE SIZE        =    189    ----
   CONSTANT SIZE    =   ----    ----
   XDATA SIZE       =   ----    ----
   PDATA SIZE       =   ----    ----
   DATA SIZE        =      4    ----
   IDATA SIZE       =   ----    ----
   BIT SIZE         =   ----    ----
END OF MODULE INFORMATION.


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