f50x_can0_receive.c

CAN of C8051F500/F510 CAN 2.0 Bus 發送跟接收Keil C source sample code.可以用在CAN 2.x的上面喔~

//-----------------------------------------------------------------------------
// F50x_CAN0_Receive.c
//-----------------------------------------------------------------------------
// Copyright 2008 Silicon Laboratories, Inc.
// http://www.silabs.com
//
// Program Description:
//
// This program receives data from another CAN node using a configurable number
// of message objects and datasize.  The message identifier is set based on the 
// message object number.  The corresponding transmit firmware is 
// F50x_CAN0_Transmit.c.  The following two #defines should be set to the
// same values in both the transmit and receive code:
//
// #define MESSAGE_OBJECTS          
// #define MESSAGE_SIZE  
//
// #define RX_COMPLETE_MASK should also be set.  See definition for details     
//
// The purpose of this example is to show how to initialize a message object
// for receive mode and how to handle certain error conditions.
//
// How To Test:
//
// 1) Verify the LED and switch pin jumpers are populated 
//    (J19 for device A and J11 for device B).
//
// 2) Make sure the CAN jumpers in J17 (for A side) and J26 (for B side)
//    are connected.
//
// 3) Download the code to a F50x-TB (either device A or device B) that is
//    connected as above to another device running the F50x_CAN0_Transmit 
//    code.
//
// 4) Run the code on the Receiver first, then run the code on the Transmitter.
//
// 5) While the receiver is waiting for transmissions, the LED will blink.
//    Once transmissions are complete, the LED will remain lit. 
//
// Target:         C8051F500 (Side B of a C8051F500-TB)
// Tool chain:     Keil C51 8.0 / Keil EVAL C51
// Command Line:   None
//
// Release 1.2 / 18 JUL 2008 (ADT)
//    - Removed Oscillator calibration
//    - Added support for reading left shifted registers on RevA devices.
//
// Release 1.1 / 11 JUN 2008 (ADT)
//    - Edited Formatting
//
// Release 1.0 / 11 MAR 2008 (GP)
//    - Initial Revision
//
//-----------------------------------------------------------------------------
// Includes
//-----------------------------------------------------------------------------

#include "compiler_defs.h"
#include "C8051F500_defs.h"            // SFR declarations

//-----------------------------------------------------------------------------
// Type Definitions
//-----------------------------------------------------------------------------

typedef union UU64
{
   U32 U32[2];
   U16 U16[4];
   U8 U8[8];
} UU64;

//-----------------------------------------------------------------------------
// Function Prototypes
//-----------------------------------------------------------------------------

void OSCILLATOR_Init (void);
void PORT_Init (void);
void CAN0_Init (void);

INTERRUPT_PROTO (CAN0_ISR, INTERRUPT_CAN0);

//-----------------------------------------------------------------------------
// Global Constants
//-----------------------------------------------------------------------------

#define SYSCLK       24000000          // System clock speed in Hz

#define MESSAGE_OBJECTS    32          // Number of message objects to use
                                       // Range is 1-32
#define MESSAGE_SIZE        8          // Size in bytes of each CAN message
                                       // Range is 1-8

#define RX_COMPLETE_MASK  0xFFFFFFFF   // Set this to (2^MESSAGE_OBJECTS - 1)

//-----------------------------------------------------------------------------
// Bit Definition Masks
//-----------------------------------------------------------------------------

// CAN0STAT
#define BOff  0x80                     // Busoff Status
#define EWarn 0x40                     // Warning Status
#define EPass 0x20                     // Error Passive
#define RxOk  0x10                     // Receive Message Successfully
#define TxOk  0x08                     // Transmitted Message Successfully
#define LEC   0x07                     // Last Error Code

//-----------------------------------------------------------------------------
// Pin Definitions
//-----------------------------------------------------------------------------

SBIT (LED, SFR_P1, 3);                 // LED = 1 turns on the LED

//-----------------------------------------------------------------------------
// Global Variables
//-----------------------------------------------------------------------------

bit CAN_ERROR = 0;                     // 0 = No Errors occurred
                                       // 1 = Some error(s) occurred

UU32 CAN_RX_COMPLETE;                  // Bit status register that is updated
                                       // when a RX complete is received for
                                       // a specific message object.  Should be
                                       // equal to RX_COMPLETE_MASK when done

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

void main (void)
{ 
   U16 iter;                           // Loop counter

   SFRPAGE = ACTIVE_PAGE;              // Set for PCA0MD

   PCA0MD &= ~0x40;                    // Disable Watchdog Timer

   OSCILLATOR_Init ();                 // Initialize oscillator
   PORT_Init ();                       // Initialize crossbar and GPIO
   CAN0_Init ();                       // Start CAN peripheral

   CAN_RX_COMPLETE.U32 = 0x0000;       // Initialize as no messages received

   EIE2 |= 0x02;                       // Enable CAN interupts
   EA = 1;                             // Enable global interrupts

   // While all messages have not been received, blink the LED
   while ((CAN_RX_COMPLETE.U32 != RX_COMPLETE_MASK) || (CAN_ERROR))
   {
      LED = !LED;
      for (iter = 0; iter < 65000; iter++);
   }

   // Once all transmissions are complete, keep the LED on
   LED = 1;                            // Turn on LED

   while (1);
}

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

//-----------------------------------------------------------------------------
// OSCILLATOR_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters   : None
//
// Initialize the internal oscillator to 24 MHz
//
//-----------------------------------------------------------------------------
void OSCILLATOR_Init (void)
{
   U8 SFRPAGE_save = SFRPAGE;
   SFRPAGE = CONFIG_PAGE;

   OSCICN = 0x87;                      // Set internal oscillator divider to 1

   SFRPAGE = SFRPAGE_save;
}

//-----------------------------------------------------------------------------
// PORT_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters   : None
//
// This function configures the crossbar and ports pins.
//
// P0.6   digital  push-pull        CAN TX
// P0.7   digital  open-drain       CAN RX
//
// P1.3   digital  push-pull        LED
//
//-----------------------------------------------------------------------------

void PORT_Init (void)
{
   U8 SFRPAGE_save = SFRPAGE;
   SFRPAGE  = CONFIG_PAGE;             // Port SFR's on Configuration page

   P0MDOUT  |= 0x40;                   // P0.6 (CAN0 TX) is push-pull
   P1MDOUT  |= 0x08;                   // P1.3 (LED) is push-pull

   XBR0     = 0x02;                    // Enable CAN0 on Crossbar
   XBR2     = 0x40;                    // Enable Crossbar and weak pull-ups

   SFRPAGE = SFRPAGE_save;
}

//-----------------------------------------------------------------------------
// CAN0_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters   : None
//
// This function initializes the CAN peripheral and all of the message objects
//
// The following settings are chosen for the peripheral and message objects:
//
// CAN Bit Clock : 1 Mbps
// Auto Retransmit : Automatic Retransmission is enabled
// MsgVal        : Set to Valid based on the #define MESSAGE_OBJECTS
// Filtering     : Enabled for all valid message objects
// Message Identifier : 11-bit standard; Each message object is only used by