基于CAN总线的通讯子程序.docx

1、基于CAN总线的通讯子程序接收程序：/-/ F04x_CAN1.c/-/ DEVICE: C8051F040/ AUTHOR: LS/ TOOLS: Keil C-compiler and Silicon Labs IDE/ CAN1.c and CAN2.c are a simple example of configuring a CAN network to/ transmit and receive data on a CAN network, and how to move information to/ and from CAN RAM message objects. Each

2、C8051F040-TB CAN node is configured/ to send a message when its P3.7 button is depressed/released, with a 0x11/ to indicate the button is pushed, and 0x00 when released. Each node also has/ a message object configured to receive messages. The C8051 tests the/ received data and will turn on/off the t

3、arget boards LED. When one target/ is loaded with CAN2.c and the other is loaded with CAN1.c, one target/ boards push-button will control the other target boards LED, establishing/ a simple control link via the CAN bus and can be observed directly on the/ target boards./ Includes/#include / SFR decl

4、arations/ CAN Protocol Register Index for CAN0ADR, from TABLE 18.1 of the C8051F040/ datasheet/#define CANCTRL 0x00 /Control Register#define CANSTAT 0x01 /Status register#define ERRCNT 0x02 /Error Counter Register#define BITREG 0x03 /Bit Timing Register#define INTREG 0x04 /Interrupt Low Byte Registe

5、r#define CANTSTR 0x05 /Test register#define BRPEXT 0x06 /BRP Extension Register/IF1 Interface Registers/#define IF1CMDRQST 0x08 /IF1 Command Rest Register#define IF1CMDMSK 0x09 /IF1 Command Mask Register#define IF1MSK1 0x0A /IF1 Mask1 Register#define IF1MSK2 0x0B /IF1 Mask2 Register#define IF1ARB1 0

6、x0C /IF1 Arbitration 1 Register#define IF1ARB2 0x0D /IF1 Arbitration 2 Register#define IF1MSGC 0x0E /IF1 Message Control Register#define IF1DATA1 0x0F /IF1 Data A1 Register#define IF1DATA2 0x10 /IF1 Data A2 Register#define IF1DATB1 0x11 /IF1 Data B1 Register#define IF1DATB2 0x12 /IF1 Data B2 Registe

7、r/IF2 Interface Registers/#define IF2CMDRQST 0x20 /IF2 Command Rest Register#define IF2CMDMSK 0x21 /IF2 Command Mask Register#define IF2MSK1 0x22 /IF2 Mask1 Register#define IF2MSK2 0x23 /IF2 Mask2 Register#define IF2ARB1 0x24 /IF2 Arbitration 1 Register#define IF2ARB2 0x25 /IF2 Arbitration 2 Registe

8、r#define IF2MSGC 0x26 /IF2 Message Control Register#define IF2DATA1 0x27 /IF2 Data A1 Register#define IF2DATA2 0x28 /IF2 Data A2 Register#define IF2DATB1 0x29 /IF2 Data B1 Register#define IF2DATB2 0x2A /IF2 Data B2 Register/Message Handler Registers/#define TRANSREQ1 0x40 /Transmission Rest1 Registe

9、r#define TRANSREQ2 0x41 /Transmission Rest2 Register#define NEWDAT1 0x48 /New Data 1 Register#define NEWDAT2 0x49 /New Data 2 Register#define INTPEND1 0x50 /Interrupt Pending 1 Register#define INTPEND2 0x51 /Interrupt Pending 2 Register#define MSGVAL1 0x58 /Message Valid 1 Register#define MSGVAL2 0x

10、59 /Message Valid 2 Registertypedef unsigned char uchar;typedef unsigned int uint;typedef unsigned long ulong;union intchar uint tempval; struct uchar hig; uchar low; bytek; ;xdata union intchar rdata4;xdata uchar sdata8 = 0x32, 0x33,0x34, 0x35, 0xb3, 0xb4, 0xb5, 0xb6;/Global Variables/char MsgNum;c

11、har status;int i;int MOTwoIndex = 0;int MOOneIndex = 0;int StatusCopy;int RXbuffer 4;int TXbuffer 8;int MsgIntNum;int Temperature;sbit BUTTON = P37;sbit LED = P16;sfr16 CAN0DAT = 0xD8;sbit P20 = P20;sbit P21 = P21;sbit WRn = P07;sbit RDn = P06;/ Function PROTOTYPES/ Initialize Message Objectvoid cle

12、ar_msg_objects (void);/void init_msg_object_TX (char MsgNum);void init_msg_object_RX (char MsgNum, uint devID);void start_CAN (void);/void transmit_turn_LED_ON (char MsgNum);/void transmit_turn_LED_OFF (char MsgNum);void receive_data (char MsgNum);void external_osc (void);void config_IO (void);void

13、flash_LED (void);void test_reg_write (char test);void stop_CAN (void);/ MAIN Routine/void main (void) / disable watchdog timer WDTCN = 0xde; WDTCN = 0xad; /configure Port I/O config_IO(); / switch to external oscillator external_osc();/ Configure CAN communications/ IF1 used for procedures calles by

14、 main program/ IF2 used for interrupt service procedure receive_data/ Message Object assignments:/ 0x02: Used to transmit commands to toggle its LED, arbitration number 1/ / Clear CAN RAM clear_msg_objects(); / Initialize message object to transmit data /init_msg_object_TX (0x02); /init_msg_object_T

15、X (0x03); / Initialize message object to receive data /init_msg_object_RX (0x01); init_msg_object_RX (0x01, 65); /ID = 130 / Enable CAN interrupts in CIP-51 EIE2 = 0x20; /Function call to start CAN start_CAN(); /Global enable 8051 interrupts EA = 1; /Loop and wait for interrupts while (1) /*if (BUTT

16、ON = 0) while (BUTTON = 0) transmit_turn_LED_OFF(0x03); else while (BUTTON = 1) transmit_turn_LED_ON(0x03); */ / Set up C8051F040/ Switch to external oscillatorvoid external_osc (void) int n; / local variable used in delay FOR loop. SFRPAGE = CONFIG_PAGE; / switch to config page to config oscillator

17、 OSCXCN = 0x77; / start external oscillator; 22.1 MHz Crystal / system clock is 22.1 MHz / 2 = 11.05 MHz for (n=0;n255;n+); / delay about 1ms while (OSCXCN & 0x80) = 0); / wait for oscillator to stabilize CLKSEL |= 0x01; / switch to external oscillatorvoid config_IO (void) SFRPAGE = CONFIG_PAGE; /Po

18、rt SFRs on Configuration page XBR3 = 0x80; / Configure CAN TX pin (CTX) as push-pull digital output P1MDOUT |= 0x40; / Configure P1.6 as push-pull to drive LED XBR2 = 0x40; / Enable Crossbar/low ports/enable P2.0 as push-pull output P2MDOUT |= 0x03; /enable P0.7 P0MDOUT |= 0x80; /enable P0.6 P0MDOUT

19、 |= 0x40; /enable P3 推挽输出 P3MDOUT = 0xff; /P3 漏极开路输出 /P3MDOUT = 0x00; /P3MDIN = 0xff;/P3 数字输入/set P2.0, P2.1/ P20 = 0; / P21 = 0; /set XMIF wrn WRn = 0; RDn = 1;/CAN Functions/Clear Message Objectsvoid clear_msg_objects (void) SFRPAGE = CAN0_PAGE; CAN0ADR = IF1CMDMSK; / Point to Command Mask Registe

20、r 1 CAN0DATL = 0xFF; / Set direction to WRITE all IF registers to Msg Obj for (i=1;i33;i+) CAN0ADR = IF1CMDRQST; / Write blank (reset) IF registers to each msg obj CAN0DATL = i; /Initialize Message Object for RXvoid init_msg_object_RX (char MsgNum, uint devID) uint temp; SFRPAGE = CAN0_PAGE; CAN0ADR

21、 = IF1CMDMSK; / Point to Command Mask 1 CAN0DAT = 0x00BB; / Set to WRITE, and alter all Msg Obj except ID MASK / and data bits CAN0ADR = IF1ARB1; / Point to arbitration1 register CAN0DAT = 0x0000; / Set arbitration1 ID to 0 /CAN0DAT = 0x8004; / Arb2 high byte:Set MsgVal bit, no extended ID, can2.c C

22、AN0DAT = 0x8000; / Dir = RECEIVE temp = devID 2; temp &= 0x1fff; / 000 ID28-ID16 temp |= 0x8000; CAN0DAT = temp; /CAN0DAT = 0x8000; CAN0DAT = 0x0482; / Msg Cntrl: set RXIE, remote frame function disabled / DLC = 4; CAN0ADR = IF1CMDRQST; / Point to Command Request reg. CAN0DATL = MsgNum; / Select Msg

23、 Obj passed into function parameter list / -initiates write to Msg Obj / 3-6 CAN clock cycles to move IF register contents to the Msg Obj in CAN RAM/Initialize Message Object for TX/*void init_msg_object_TX (char MsgNum) SFRPAGE = CAN0_PAGE; CAN0ADR = IF2CMDMSK; / Point to Command Mask 1 CAN0DAT = 0

24、x00B2; / Set to WRITE, & alter all Msg Obj except ID MASK bits CAN0ADR = IF2ARB1; / Point to arbitration1 register CAN0DAT = 0x0000; / Set arbitration1 ID to highest priority CAN0DAT = 0xA000; / Autoincrement to Arb2 high byte: can2.c CAN0DAT = 0xA004; / Set MsgVal bit, no extended ID, Dir = WRITE CAN0DAT = 0x0081; / Msg Cntrl: DLC = 1, remote frame function not enabled CAN0ADR = IF2CMDRQST; / Point to Command Req