spi_ee_f30x.c

spi的几种工作模式。可能有点乱

//-----------------------------------------------------------------------------
// SPI_EE_F30x.c
//-----------------------------------------------------------------------------
// Copyright 2001 Cygnal Integrated Products, Inc.
//
// AUTH: BD
// DATE: 14 DEC 01
//
// This program demonstrates how a collection of SPI master routines for the 
// 8051F30x devices can be used in a C program.
//
// In this example, a Microchip 25LC320 4k X 8 Serial EEPROM is interfaced to a
// SPI master device implemented in the C8051F30x. The EEPROM is written with 
// two test patterns: 1) all locations are 0xFF and 2) each location is written 
// with the LSB of the corresponding address.
// The EEPROM contents are then verified with the test patterns.  If the test
// patterns are verified with no errors, the LED blinks on operation completion.
// Otherwise, the LED stays off.  Progress can also be monitored by a terminal
// connected to UART0 operating at 115.2kbps.
//
// For this code to be functional, *one* of the following files should also be
// compiled or assembled, and the resulting object file must be linked to the
// object file produced from this code:
//
//    SPI_MODE0.c    Mode 0 SPI Master Implementation in C
//    SPI_MODE0.asm  Mode 0 SPI Master Implementation in Assembly
//    SPI_MODE3.c    Mode 3 SPI Master Implementation in C
//    SPI_MODE3.asm  Mode 3 SPI Master Implementation in Assembly
//
//    This EEPROM's serial port will only operate with a Mode 0 or Mode 3
//    SPI configuration.
//
// Target: C8051F30x
// Tool chain: KEIL C51 6.03 / KEIL EVAL C51
//

//-----------------------------------------------------------------------------
// Includes
//-----------------------------------------------------------------------------

#include <c8051f300.h>                 // SFR declarations
#include <stdio.h>                     // Standard I/O
#include "SPI_defs.h"                  // SPI port definitions

//-----------------------------------------------------------------------------
// 16-bit SFR Definitions for 'F30x
//-----------------------------------------------------------------------------

sfr16 DP       = 0x82;                 // data pointer
sfr16 TMR2RL   = 0xca;                 // Timer2 reload value
sfr16 TMR2     = 0xcc;                 // Timer2 counter
sfr16 PCA0CP1  = 0xe9;                 // PCA0 Module 1 Capture/Compare
sfr16 PCA0CP2  = 0xeb;                 // PCA0 Module 2 Capture/Compare
sfr16 PCA0     = 0xf9;                 // PCA0 counter
sfr16 PCA0CP0  = 0xfb;                 // PCA0 Module 0 Capture/Compare

//-----------------------------------------------------------------------------
// Global CONSTANTS
//-----------------------------------------------------------------------------

#define  SYSCLK      24500000          // SYSCLK frequency in Hz
#define  BAUDRATE    115200            // Baud rate of UART in bps

#define  EE_SIZE     4096              // EEPROM size in bytes
#define  EE_READ     0x03              // EEPROM Read command
#define  EE_WRITE    0x02              // EEPROM Write command
#define  EE_WRDI     0x04              // EEPROM Write disable command
#define  EE_WREN     0x06              // EEPROM Write enable command
#define  EE_RDSR     0x05              // EEPROM Read status register
#define  EE_WRSR     0x01              // EEPROM Write status register

sbit     LED = P0^6;                   // LED Indicator

//-----------------------------------------------------------------------------
// Function PROTOTYPES
//-----------------------------------------------------------------------------

void PORT_Init (void);                 // Port I/O configuration
void SYSCLK_Init (void);               // SYSCLK Initialization
void UART0_Init (void);                // UART0 Initialization

extern char SPI_Transfer (char);       // SPI Transfer routine

void Timer0_ms (unsigned ms);
void Timer0_us (unsigned us);

unsigned char EE_Read (unsigned Addr);
void EE_Write (unsigned Addr, unsigned char value);

                                                      
//-----------------------------------------------------------------------------
// Global VARIABLES
//-----------------------------------------------------------------------------


//-----------------------------------------------------------------------------
// MAIN Routine
//-----------------------------------------------------------------------------

void main (void) {

   unsigned EE_Addr;                   // address of EEPROM byte
   unsigned char test_byte;

   // Disable Watchdog timer
   PCA0MD &= ~0x40;                    // WDTE = 0 (clear watchdog timer 
                                       // enable)

   SYSCLK_Init ();                     // initialize oscillator
   PORT_Init ();                       // initialize ports and GPIO
   UART0_Init ();                      // initialize UART0
   EA = 1;                             // enable global interrupts

   SCK = 0;

   // fill EEPROM with 0xFF's
   LED = 1;
   for (EE_Addr = 0; EE_Addr < EE_SIZE; EE_Addr++) 
   {
      test_byte = 0xff;
      EE_Write (EE_Addr, test_byte);

      // print status to UART0
      if ((EE_Addr % 16) == 0) 
      {
         printf ("\nwriting 0x%04x: %02x ", EE_Addr, (unsigned) test_byte);
      } 
      else 
      {
         printf ("%02x ", (unsigned) test_byte);
      }
   }

   // verify EEPROM with 0xFF's
   LED = 0;
   for (EE_Addr = 0; EE_Addr < EE_SIZE; EE_Addr++) 
   {
      test_byte = EE_Read (EE_Addr);

      // print status to UART0
      if ((EE_Addr % 16) == 0) 
      {
         printf ("\nverifying 0x%04x: %02x ", EE_Addr, (unsigned) test_byte);
      } 
      else 
      {
         printf ("%02x ", (unsigned) test_byte);
      }
      if (test_byte != 0xFF) 
      {
         printf ("Error at %u\n", EE_Addr);
         while (1);                    // stop here on error
      }
   }

   // fill EEPROM memory with LSB of EEPROM address.
   LED = 1;
   for (EE_Addr = 0; EE_Addr < EE_SIZE; EE_Addr++) 
   {
      test_byte = EE_Addr & 0xff;
      EE_Write (EE_Addr, test_byte);

      // print status to UART0
      if ((EE_Addr % 16) == 0) 
      {
         printf ("\nwriting 0x%04x: %02x ", EE_Addr, (unsigned) test_byte);
      } 
      else 
      {
         printf ("%02x ", (unsigned) test_byte);
      }
   }

   // verify EEPROM memory with LSB of EEPROM address
   LED = 0;
   for (EE_Addr = 0; EE_Addr < EE_SIZE; EE_Addr++) 
   {
      test_byte = EE_Read (EE_Addr);

      // print status to UART0
      if ((EE_Addr % 16) == 0) 
      {
         printf ("\nverifying 0x%04x: %02x ", EE_Addr, (unsigned) test_byte);
      } 
      else 
      {
         printf ("%02x ", (unsigned) test_byte);
      }
      if (test_byte != (EE_Addr & 0xFF)) 
      {
         printf ("Error at %u\n", EE_Addr);
         while (1);                    // stop here on error
      }
   }

   while (1) 
   {                                   // Flash LED when done
      Timer0_ms (100);
      LED = ~LED;
   }
}

//-----------------------------------------------------------------------------
// Subroutines
//-----------------------------------------------------------------------------

//-----------------------------------------------------------------------------
// Initialization Subroutines
//-----------------------------------------------------------------------------

//-----------------------------------------------------------------------------
// PORT_Init
//-----------------------------------------------------------------------------
//
// Configure the Crossbar and GPIO ports.
// P0.0 - MOSI (push-pull)
// P0.1 - MISO
// P0.2 - SCK (push-pull)
// P0.3 - NSS (push-pull)
// P0.4 - UART TX (push-pull)
// P0.5 - UART RX
// P0.6 - LED