MCP2515滤波配置

1、MCP2515的接收滤波功能相关的寄存器以及滤波逻辑滤波寄存器EXIDE: 0报文滤波仅用于标准帧 1报文滤波仅用于扩展帧对扩展帧进行滤波的时候，EXIDE位必须设置为1，对标准帧滤波时设置为0屏蔽寄存器对标准帧滤波时，即对标准帧的11bit标识符按比特进行滤波；对扩展帧进行滤波的时候，即是对扩展帧的29位标识符按比特进行滤波。当新报文符合验收滤波条件并被载入接收缓冲器时,使能报文接收的滤波器编号将被装载到RXBnCTRL寄存器FILHIT位中。接收到的信息首先在RXB0中进行滤波匹配，不满足的话则到RXB1中进行滤波匹配。只要满足一个滤波寄存器的条件，则接收该报文。如果将RXB0CTRL寄存

2、器的BUKT位置1，则将使能接收滚存功能（接收缓冲器0满之后可以将新接收到的数据滚存到缓存器1），打开接收滤波功能之后，如果缓冲器0已满，同时又收到一个符合缓冲器0滤波条件的报文，那么该报文将滚存到缓冲器1，不管是否满足缓冲器1的滤波条件。2515位定时相关配置标称比特率（Nominal Bit Rate， NBR）定义为在不需要再同步的情况下，理想发送器每秒发送的位数，它可用下面的公式来表示：标称位时间（Nominal Bit Time， NBT）（tbit）由互不重叠的段时间段组成（图5-1）。因此NBT 为下列时间段之和：组成位时间的每个段都由时间份额（TQ）组成。每个时间份额的长度取决

3、于振荡器周期（tOSC）。通常TQ为两个振荡器周期。图5-2 显示了如何从TOSC 和TQ推导出位周期。TQ 的长度等于一个TQ 时钟周期（tBRPCLK），利用称为波特率预分频器（BRP）的可编程预分频器对它进行编程设置。以下公式对此进行了阐述：#include <reg52.h>#include <2510.h>#include <absacc.h>#include <intrins.h>#include <main.h>unsigned char board_addr=0x01;/接口板地址unsigned char contr

4、oler_addr=100;/控制器地址unsigned char transmit_dat13=0x40,0x08,100,0x01,0x08,1,2,3,4,5,6,7,8;/can发送数据缓存unsigned char receive_dat13=0;/can接收数据缓存unsigned char cnt=0;unsigned char m_data=0;bit report_register_inf_flag=0;bit loop_register_over_flag=1;unsigned char code register_inf255=0x01,0x02,0xFF,0x05,0x

5、06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x56,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x

6、06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0xFF,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06, 0x01,0x02,0xFF,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0xFF,0x05,0

7、x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0

8、x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06, 0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,

9、0x06,0x01,0x02,0x03,0x05,0x06,0x01,0x02,0x03,0x05,0x06;void main() unsigned char register_inf_cnt=0; unsigned char loop_cnt=0; TMOD=0x11; /使用定时器T0，设为16位定时器（工作方式1），晶振11.0592M,中断时间T=(216-19456)×12/11.0592=50ms TH0=0x4C;/设置定时器T0初值194564C00H TL0=0x00; PT0=1;/设置定时器T0中断为高优先级 TR0=1;/定时0开始 ET0=1;/允许定时器

10、T0中断 UP_DOWN = 0;/选中内部ram和8255地址空间 Control_8255 = 0x90;/方式0，A口输入，B口输出，C口输出/* /使用定时器T1，设为16位定时器（工作方式1），晶振11.0592M,中断时间T=70ms TH1=0x04;/设置定时器T1初值 TL1=0x00; TR1=1;/定时1开始 ET1=1;/允许定时器T1中断*/ IT1=0;/设置INT1为电平触发 EX1=1;/允许外部INT1中断(2510) mcp2515_init(); init_filter(controler_addr,board_addr); /ENTER_LOOP_MOD

11、E();/进入回环模式 /m_data=spi_read_register(CANCTRL); EA=1;/开总中断 delay_1ms(200); /transmit_dat0=PRIORITY5| TI_SignalBoardRegister; /mcp2515_TX(); while(1) if(report_register_inf_flag=1) if(loop_register_over_flag=1) transmit_dat0=PRIORITY5 | TI_RegisterInfReport; transmit_dat1=0x08; transmit_dat2=board_ad

12、dr; transmit_dat3=controler_addr; transmit_dat4=0x07; transmit_dat12=0xFF; for(loop_cnt=1;loop_cnt<=4;loop_cnt+) transmit_dat5=loop_cnt;/回路编号 for(register_inf_cnt=0;register_inf_cnt<51;register_inf_cnt+) transmit_dat6=register_inf_cnt*5+1; transmit_dat7=register_infregister_inf_cnt*5; transmit

13、_dat8=register_infregister_inf_cnt*5+1; transmit_dat9=register_infregister_inf_cnt*5+2; transmit_dat10=register_infregister_inf_cnt*5+3; transmit_dat11=register_infregister_inf_cnt*5+4; mcp2515_TX(); register_inf_cnt=0; /上报登记结束命令 transmit_dat0=PRIORITY5 | TI_RegisterOver; transmit_dat1=0x08; transmi

14、t_dat2=board_addr; transmit_dat3=controler_addr; transmit_dat4=0x00; mcp2515_TX(); report_register_inf_flag=0; /=/ T0定时器中断服务程序，喂看门狗/=void Timer0_Int() interrupt 1 using 0static unsigned char count=0; TR0=0;/定时0停止 ET0=0;/关闭定时器T0中断/设置定时初值1945654C05H (弥补中断响应及重新赋值间的时间间隔5)TH0=0x4C;TL0=0x05;UP_DOWN = 0;if

15、(count%2=0)PC_8255 = 0x00;elsePC_8255 = 0x10;count+;TR0=1;/定时0开始ET0=1;/允许定时器T0中断/=/ 功能：外部中断1，2510中断服务程序/ 入口：无/ 出口：无/ 接收数据放在,receive_dat数组中/=void int1_can_RX() interrupt 2 using 0 unsigned char int_data;/中断标志位寄存器的值 unsigned char buffer_no;/接收到报文的缓冲区的编号 unsigned char priority,ti; EX1=0;/关闭单片机外部中断1 /读取

16、2510中断标志位寄存器 int_data=spi_read_register(CANINTF); if(int_data!=0xff) /报文错误中断 if( (int_data&0x80)!=0 ) spi_bit_modify(CANINTF,0x80,0x00); /接收中断 if( (int_data&0x01)!=0 | (int_data&0x02)!=0 ) if( (int_data&0x01)!=0 )/RX0 buffer_no=0x00; else if( (int_data&0x02)!=0 )/RX1 buffer_no=0x

17、01; spi_read_RX_buffer(receive_dat,buffer_no); /清除接收中断标志位 spi_bit_modify(CANINTF,buffer_no+1,0x00); /*从此处开始进行数据处理*/ priority=receive_dat0&0xE0; ti=receive_dat0&0x1F; if(priority=PRIORITY0) else if(priority=PRIORITY1) else if(priority=PRIORITY2) if(ti=TI_BroadcastRegister) /收到控制器广播的登记命令，接口板开始

18、登记下面回路 else if(priority=PRIORITY3) else if(priority=PRIORITY4) else if(priority=PRIORITY5) if(ti=TI_SignalBoardRegister) /收到控制器发送的“单接口板请求登记信息命令”，首先回复一个确认，然后待接口板下面回路登记完毕，开始上报登记信息 transmit_dat0=PRIORITY4 | TI_Ack; transmit_dat1=0x08; transmit_dat2=board_addr; transmit_dat3=controler_addr; transmit_dat

19、4=0x00; mcp2515_TX(); report_register_inf_flag=1; EX1=1;/打开单片机外部中断1#ifndef _MAIN_H_#define _MAIN_H_sbit UP_DOWN = P13;/=/ 宏定义/=#define TRUE 1#define FALSE0#define PA_8255 XBYTE0xE000#define PB_8255 XBYTE0xE001#define PC_8255 XBYTE0xE002#define Control_8255 XBYTE0xE003/协议中can数据帧优先级定义#define PRIORITY0

20、0x00#define PRIORITY10x20#define PRIORITY20x40#define PRIORITY30x60#define PRIORITY40x80#define PRIORITY50xA0/协议中TI类型码定义#defineTI_BroadcastRegister0x00#define TI_Ack 0x04#define TI_SignalBoardRegister0x11#define TI_RegisterInfReport0x12#define TI_RegisterOver 0x13#endif#include <reg52.h>#inclu

21、de <intrins.h>#include <2510.h>extern unsigned char transmit_dat13;static unsigned char spi_read_byte(void);static void spi_write_byte( unsigned char out_byte);unsigned char code RTS3=SPI_CMD_RTS_TXB0,SPI_CMD_RTS_TXB1,SPI_CMD_RTS_TXB2;#define STRAT_TRANSMIT(x) sclk=0;scs=0; spi_write_byt

22、e(RTSx); scs=1;sclk=1; #define SPI_RESET_2515() sclk=0;scs=0; spi_write_byte(SPI_CMD_RESET); scs=1;sclk=1; /* * fn spi_bit_modify * * brief spi command ,modify 2515's register by bit * * param addr- register's addressmask- bit maskdat- dat to modify * * return none */void spi_bit_modify(unsi

23、gned char addr, unsigned char mask, unsigned char dat)sclk=0;scs=0;spi_write_byte(SPI_CMD_BITCHANGE);spi_write_byte(addr);spi_write_byte(mask);spi_write_byte(dat);scs=1;sclk=1;/* * fn spi_get_2515_status * * brief spi command ,get 2515's "Read Status" or "RX Status" * * param

24、 cmd - 2515 spi instruction (SPI_CMD_READ_STATUS or SPI_CMD_RX_STATUS) * * return status register */unsigned char spi_get_2515_status(unsigned char cmd) unsigned char status; sclk=0;scs=0; spi_write_byte(cmd); status=spi_read_byte(); scs=1;sclk=1; return status;/* * fn mcp2510_init * * brief init 25

25、15，config some registers * * param none * * return none */void mcp2515_init(void)/2510硬件复位canrest=0;delay_1ms(10);canrest=1;delay_1ms(10); /软复位2510SPI_RESET_2515();SPI_RESET_2515(); /配置引脚控制和状态寄存器spi_write_register(BFPCTRL,0x00);/RXnBF(禁止引脚功能)spi_write_register(TXRTSCTRL,0x07);/TXnRTS引脚控制和状态寄存器 /配置位定

26、时寄存器配置spi_write_register(CNF3,0x02);spi_write_register(CNF2,0xD0);spi_write_register(CNF1,0x04);/100k/spi_write_register(CNF1,0x31);/10k /配置中断相关的寄存器spi_write_register(CANINTE,0x83);/打开报文接收接收、报文错误中断spi_write_register(CANINTF,0x00);spi_write_register(EFLG,0x00); /配置发送缓冲器的控制寄存器spi_write_register(TXB0CT

27、RL,0x03);spi_write_register(TXB1CTRL,0x00);spi_write_register(TXB1CTRL,0x00); /配置接收缓冲器的控制寄存器spi_write_register(RXB0CTRL,0x64);spi_write_register(RXB1CTRL,0x60);ENTER_NORMAL_MODE();/* * fn mcp2510_TX * * brief transmit the data in global array "transmit_dat13",if the 2515's transmit *bu

28、ffer is full,then return * * param none * * return none */void mcp2515_TX(void)unsigned char TX_Buf_Number;/检测可用缓冲区if( ( spi_read_register(TXB0CTRL) & 0x08 )=0 )/使用发送缓冲器TX0TX_Buf_Number=0;else if( ( spi_read_register(TXB1CTRL) & 0x08 )=0 )/使用发送缓冲器TX1TX_Buf_Number=1;else if( ( spi_read_regist

29、er(TXB2CTRL) & 0x08 )=0 )/使用发送缓冲器TX2TX_Buf_Number=2;elsereturn;/都不可用，返回/装填数据spi_write_TX_buffer(transmit_dat, TX_Buf_Number);/启动发送 STRAT_TRANSMIT(TX_Buf_Number);unsigned char code mask_config8=0xC0,/* RXM0SIDH 对2bit滤波 */0x00,/* RXM0SIDL */0xFF,/* RXM0EID8 对8bit滤波 */0x00,/* RXM0EID0 */0x00,/* RXM

30、1SIDH */0x00,/* RXM1SIDL */0xFF,/* RXM1EID8 对8bit滤波 */0xFF,/* RXM1EID0 对8bit滤波 */;void init_filter(unsigned char controlerAddr,unsigned char boardAddr)unsigned char filter_config4;/进入配置模式ENTER_CONFIG_MODE();/配置验收滤波屏蔽寄存器spi_write_register_continue(mask_config, RXM0SIDH, 8);/配置BUFFER 0 的验收滤波寄存器filter_

31、config0=0x40;/RXF0-1SIDHfilter_config1=0x08;/RXF0-1SIDL，报文滤波应用于扩展帧filter_config2=controlerAddr;/RXF0-1EID8，设置为控制器地址filter_config3=0x00;/RXF0-1EID0spi_write_register_continue(filter_config, RXF0SIDH, 4);spi_write_register_continue(filter_config, RXF1SIDH, 4);/配置BUFFER 1 的验收滤波寄存器filter_config0=0x00;/R

32、XF2-5SIDHfilter_config1=0x08;/RXF2-5SIDL，报文滤波应用于扩展帧filter_config2=controlerAddr;/RXF2-5EID8，设置为控制器地址filter_config3=boardAddr;/RXF2-5EID0，设置为接口板地址spi_write_register_continue(filter_config, RXF2SIDH, 4);spi_write_register_continue(filter_config, RXF3SIDH, 4);spi_write_register_continue(filter_config,

33、RXF4SIDH, 4);spi_write_register_continue(filter_config, RXF5SIDH, 4);/配置接收缓冲器的控制寄存器spi_write_register(RXB0CTRL,0x04);/使能buffer0的接收滤波功能spi_write_register(RXB1CTRL,0x00);/使能buffer1的接收滤波功能/进入正常模式ENTER_NORMAL_MODE();/* * fn spi_write_TX_buffer * * brief write TX buffer 0 or 1 or 2 * * param buffer- data

34、 buffer * bufferNo - buffer number * * return none */unsigned char code TX_BUFFER_HEAD_ADDR3=TXB0SIDH,TXB1SIDH,TXB2SIDH;void spi_write_TX_buffer(unsigned char* buffer, unsigned char bufferNo) unsigned char i; sclk=0;scs=0; spi_write_byte(SPI_CMD_WRITE); /发送写指令 spi_write_byte(TX_BUFFER_HEAD_ADDRbuffe

35、rNo);/指定起始地址 /写取帧头 spi_write_byte(buffer0); spi_write_byte(buffer1); spi_write_byte(buffer2); spi_write_byte(buffer3); spi_write_byte(buffer4); /写帧数据域 for(i=1;(i<=buffer4)&&(i<=8);i+) spi_write_byte(buffer4+i); scs=1;sclk=1;/* * fn spi_read_RX_buffer * * brief read RX buffer 0 or 1 * *

36、 param buffer- data buffer * bufferNo - buffer number * * return the data of the register */unsigned char code RX_BUFFER_HEAD_ADDR2=RXB0SIDH,RXB1SIDH;void spi_read_RX_buffer(unsigned char* buffer, unsigned char bufferNo) unsigned char i; sclk=0;scs=0; spi_write_byte(SPI_CMD_READ); /发送读命令 spi_write_b

37、yte(RX_BUFFER_HEAD_ADDRbufferNo);/指定起始地址 /先读取帧头数据 buffer0=spi_read_byte(); buffer1=spi_read_byte(); buffer2=spi_read_byte(); buffer3=spi_read_byte(); buffer4=spi_read_byte(); /读取帧数据域 for(i=1;(i<=buffer4)&&(i<=8);i+) buffer4+i=spi_read_byte(); scs=1;sclk=1;void spi_write_register(unsign

38、ed char addr,unsigned char dat) sclk=0;scs=0; spi_write_byte(SPI_CMD_WRITE);/发送写指令 spi_write_byte(addr);/地址 spi_write_byte(dat);/数据 scs=1;sclk=1;/* * fn spi_write_register_continue * * brief write n bytes to 2515's register with continuous address * * param buffer- data buffer *addr- the start a

39、ddress *cnt- the number of the bytes to write * * return none */void spi_write_register_continue(unsigned char* buffer, unsigned char addr, unsigned char cnt) unsigned char i; sclk=0;scs=0; spi_write_byte(SPI_CMD_WRITE);/发送写命令 spi_write_byte(addr);/指定地址 for(i=0;i<cnt;i+) spi_write_byte(bufferi);/

40、写数据 scs=1;sclk=1;unsigned char spi_read_register(unsigned char addr) unsigned char read_dat; sclk=0;scs=0; _nop_ (); spi_write_byte(SPI_CMD_READ);/发送读命令 spi_write_byte(addr);/指定地址 read_dat=spi_read_byte();/读取数据 _nop_ (); scs=1;sclk=1; return(read_dat);/* * fn spi_read_register_continue * * brief read n bytes from 2515's register