C51 COMPILER V6.00 XBUS                                                                    05/18/2000 08:49:51 PAGE 1   


C51 COMPILER 6.00, COMPILATION OF MODULE XBUS
NO OBJECT MODULE REQUESTED
COMPILER INVOKED BY: D:\Keil\C51\BIN\C51.EXE .\Xbus.c OBJECTEXTEND DEBUG

stmt level    source

*** WARNING 500 IN LINE 1 OF .\XBUS.C: MISSING DEVICE (SECURITY KEY NOT FOUND)
   1          
   2          #include <reg51.h>
   3          
   4          // #define RESETBUS
   5          
   6          /* 0xc0 = NOP  0xd0 = Addr  0xe0 = Write  0xf0 = Read */
   7          /* outputs */
   8          sbit STROBE = P3^7;  /* clock pin is P3.7 */
   9          sbit COM1   = P1^5;  /* command1 pin is P1.5 */
  10          sbit COM0   = P1^4;  /* command0 pin is P1.4 */
  11          sbit DATA3 = P1^3;   /* data3 pin is P1.3 */
  12          sbit DATA2 = P1^2;   /* data2 pin is P1.2 */
  13          sbit DATA1 = P1^1;   /* data1 pin is P1.1 */
  14          sbit DATA0 = P1^0;   /* data0 pin is P1.0 */
  15          
  16          #define NOPCOM 0x00
  17          #define ADDRCOM 0x10
  18          #define READCOM 0x30
  19          #define WRITECOM 0x20
  20          
  21          /* macro definitions */
  22          #define AddrNibl0(addr)\
  23          	P1 = (0xC0 | ADDRCOM | (addr & 0xf));	\
  24          	STROBE = 1; STROBE = 0; /* clock it */
  25          
  26          #define AddrNibl1(addr)\
  27          	P1 = (0xC0 | ADDRCOM | ((addr>>4) & 0xf));\
  28          	STROBE = 1; STROBE = 0; /* clock it */
  29          
  30          #define AddrNibl2(addr)\
  31          	P1 = (0xC0 | ADDRCOM | ((addr>>8) & 0xf));\
  32          	STROBE = 1; STROBE = 0; /* clock it */
  33          
  34          #define AddrNibl3(addr)\
  35          	P1 = (0xC0 | ADDRCOM | ((addr>>12) & 0xf));\
  36          	STROBE = 1; STROBE = 0; /* clock it */
  37          
  38          #define WriteNibl0(value)\
  39          	P1 = (0xC0 | WRITECOM | (value & 0xf));\
  40          	STROBE = 1; STROBE = 0; /* clock it */
  41          
  42          // The FPGA pulls down on STROBE to cause us to wait
  43          #define WriteNibl1(value) \
  44          	P1 =(0xC0 | WRITECOM | ((value>>4) & 0xf)); \
  45          	STROBE = 1; \
  46          	while (STROBE==0) {}; /* Wait for FPGA to release STROBE */ \
  47          	STROBE = 0;
  48          
  49          // We have to tristate the data lines with the 0xf
  50          // The FPGA pulls down on STROBE until the read data is ready
  51          #define ReadNibl0(value) \
  52          	P1 = (0xC0 | READCOM | 0xf); /* Remember to tristate data lines! */ \
  53          	STROBE = 1; /* clock it */ \
  54          	while ( STROBE==0 ) {} /* Wait until FPGA is ready */ \
C51 COMPILER V6.00 XBUS                                                                    05/18/2000 08:49:51 PAGE 2   

  55          	value = (P1 & 0x0f); \
  56          	STROBE = 0;
  57          
  58          #define ReadNibl1(value)\
  59          	P1 = (0xC0 | READCOM | 0xf); /* Remember to tristate data lines */ \
  60          	STROBE = 1; /* clock it */\
  61          	value = ((P1 << 4) | value); \
  62          	STROBE = 0;
  63          
  64          unsigned char XRead(unsigned int address)
  65          {
  66   1      	unsigned char value;
  67   1      
  68   1      	/* 16 bits of address */
  69   1      	AddrNibl0(address);
  70   1      	AddrNibl1(address);
  71   1      	AddrNibl2(address);
  72   1      	AddrNibl3(address);
  73   1          /* read the data bits back */
  74   1      	ReadNibl0(value);
  75   1      	ReadNibl1(value);
  76   1      	return value;
  77   1      }
  78          
  79          void XWrite(unsigned int address, unsigned char value)
  80          {
  81   1      	/* 16 bits of address */
  82   1      	AddrNibl0(address);
  83   1      	AddrNibl1(address);
  84   1      	AddrNibl2(address);
  85   1      	AddrNibl3(address);
  86   1          /* Send the data */
  87   1      	WriteNibl0(value);
  88   1      	WriteNibl1(value);
  89   1      }
  90          
  91          // Initialize the Xbus by issuing a bunch of NOPs to get
  92          // the FPGA state machine into the idle mode
  93          void XInit()
  94          {
  95   1      	P1 = 0xff;		// Tristate port 1
  96   1      	STROBE = 0;		// Start with strobe low
  97   1      	P1 = (0xC0 | NOPCOM );
  98   1      	STROBE = 1; STROBE = 0; /* clock it */
  99   1      	P1 = (0xC0 | NOPCOM );
 100   1      	STROBE = 1; STROBE = 0; /* clock it */
 101   1      	P1 = (0xC0 | NOPCOM );
 102   1      	STROBE = 1; STROBE = 0; /* clock it */
 103   1      	P1 = (0xC0 | NOPCOM );
 104   1      	STROBE = 1; STROBE = 0; /* clock it */
 105   1      	P1 = (0xC0 | NOPCOM );
 106   1      	STROBE = 1; STROBE = 0; /* clock it */
 107   1      	P1 = (0xC0 | NOPCOM );
 108   1      	STROBE = 1; STROBE = 0; /* clock it */
 109   1      	P1 = (0xC0 | NOPCOM );
 110   1      	STROBE = 1; STROBE = 0; /* clock it */
 111   1      	P1 = (0xC0 | NOPCOM );
 112   1      	STROBE = 1; STROBE = 0; /* clock it */
 113   1      }
 114          
 115          unsigned char XReadCont()
 116          {
C51 COMPILER V6.00 XBUS                                                                    05/18/2000 08:49:51 PAGE 3   

 117   1      	unsigned char value;
 118   1      	ReadNibl0(value);
 119   1      	ReadNibl1(value);
 120   1      	return value;
 121   1      }
 122          
 123          	


MODULE INFORMATION:   STATIC OVERLAYABLE
   CODE SIZE        =    275    ----
   CONSTANT SIZE    =   ----    ----
   XDATA SIZE       =   ----    ----
   PDATA SIZE       =   ----    ----
   DATA SIZE        =   ----    ----
   IDATA SIZE       =   ----    ----
   BIT SIZE         =   ----    ----
END OF MODULE INFORMATION.


C51 COMPILATION COMPLETE.  1 WARNING(S),  0 ERROR(S)