spi_1110.lst

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C51 COMPILER V6.10  SPI_1110                                                               04/19/2001 12:00:57 PAGE 1   


C51 COMPILER V6.10, COMPILATION OF MODULE SPI_1110
OBJECT MODULE PLACED IN .\SPI_1110.OBJ
COMPILER INVOKED BY: C:\KEIL\C51\BIN\C51.EXE .\SPI_1110.C OPTIMIZE(6,SPEED) BROWSE DEBUG OBJECTEXTEND

stmt level    source

   1          /*------------------------------------------------------------------*-
   2          
   3             SPI_1110.C (v1.00)
   4          
   5            ------------------------------------------------------------------
   6          
   7             Simple SPI library for Atmel AT89S53
   8             - allows data to be read from Max1110 / 1111 ADC
   9          
  10          
  11             COPYRIGHT
  12             ---------
  13          
  14             This code is from the book:
  15          
  16             PATTERNS FOR TIME-TRIGGERED EMBEDDED SYSTEMS by Michael J. Pont 
  17             [Pearson Education, 2001; ISBN: 0-201-33138-1].
  18          
  19             This code is copyright (c) 2001 by Michael J. Pont.
  20           
  21             See book for copyright details and other information.
  22          
  23          -*------------------------------------------------------------------*/
  24          
  25          #include "Main.H"
  26          #include "Port.H"
  27          
  28          #include "SPI_Core.h"
  29          #include "SPI_1110.h"
  30          #include "TimeoutH.h"
  31          
  32          // ------ Public variable declarations -----------------------------
  33          
  34          // The error code variable
  35          //
  36          // See Port.H for port on which error codes are displayed
  37          // and for details of error codes
  38          extern tByte Error_code_G;
  39          
  40          /*------------------------------------------------------------------*-
  41          
  42            SPI_MAX1110_Read_Byte()
  43          
  44            Read a byte of data from the ADC.
  45          
  46          -*------------------------------------------------------------------*/
  47          tByte SPI_MAX1110_Read_Byte(void)
  48             {
  49   1         tByte Data, Data0, Data1;
  50   1         
  51   1         // 0. Pin /CS is pulled low to select the device
  52   1         SPI_CS = 0;
  53   1        
  54   1         // 1. Send a MAX1110 control byte
  55   1      
C51 COMPILER V6.10  SPI_1110                                                               04/19/2001 12:00:57 PAGE 2   

  56   1         // Bit 7 = 1 (start of control byte)
  57   1         // Bit 6 = SEL2 
  58   1         // Bit 5 = SEL1 
  59   1         // Bit 4 = SEL0  (these three select the input channel, p9 MAX1110 docs)
  60   1         // Bit 3 = 1 for unipolar, 0 for bipolar
  61   1         // Bit 2 = 1 for single ended, 0 for differential
  62   1         // Bit 1 = 1 for fully operational, 0 for power-down mode
  63   1         // Bit 0 = 1 for external clock, 0 for internal clock
  64   1         //  
  65   1         // Control byte 0x8F sets single-ended unipolar mode, input channel 0 (pin 1)
  66   1         SPI_Exchange_Bytes(0x8F);
  67   1      
  68   1         // 2. The data requested is shifted out on SO by sending two dummy bytes
  69   1         Data0 = SPI_Exchange_Bytes(0x00);
  70   1         Data1 = SPI_Exchange_Bytes(0x00);
  71   1      
  72   1         // The data are contained in bits 5-0 of Data0 
  73   1         // and 7-6 of Data1 - shift these bytes to give a combined byte,
  74   1         Data0 <<= 2;   
  75   1         Data1 >>= 6;
  76   1         Data = (Data0 | Data1);
  77   1      
  78   1         // 3. We pull the /CS pin high to complete the operation
  79   1         SPI_CS = 1;
  80   1      
  81   1         // 4. We return the required data
  82   1         return Data; // Return SPI data byte
  83   1         }
  84            
  85          /*------------------------------------------------------------------*-
  86            ---- END OF FILE -------------------------------------------------
  87          -*------------------------------------------------------------------*/ 


MODULE INFORMATION:   STATIC OVERLAYABLE
   CODE SIZE        =     40    ----
   CONSTANT SIZE    =   ----    ----
   XDATA SIZE       =   ----    ----
   PDATA SIZE       =   ----    ----
   DATA SIZE        =   ----       1
   IDATA SIZE       =   ----    ----
   BIT SIZE         =   ----    ----
END OF MODULE INFORMATION.


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