DSPCAN总线发送程序，为什么发送数据后TA没有被置位？

只看该作者 · 2013-12-10 21:37

用示波器看有波形输出，但是TA却没有被置位，一直都有波形。而却TRS一直为1，发送数据后应该为0吧，照这样说应该没有发送数据，但是为什么引脚上又有矩形波形输出呢？求指导。

只看该作者 · 2013-12-10 21:38

这是程序：
#define    LED1 GpioDataRegs.GPADAT.bit.GPIO0

void main(void)
{

Uint16  j;
Uint32  k;

struct ECAN_REGS ECanbShadow;

InitSysCtrl(); //³õÊ¼»¯ÏµÍ³

InitECanGpio();//ÅäÖÃGPIOÒý½Å

DINT;
InitPieCtrl();//³õÊ¼»¯PIEÖÐ¶Ï

IER = 0x0000;//¹ØÖÐ¶Ï
IFR = 0x0000;

InitPieVectTable();//³õÊ¼»¯PIEÖÐ¶ÏÊ¸Á¿±í

MessageReceivedCount = 0;
ErrorCount = 0;
PassCount = 0;

EALLOW;//ÅäÖÃeCANµÄRXºÍTX·Ö±ðÎªeCANµÄ½ÓÊÕºÍ·¢ËÍÒý½Å
ECanbShadow.CANTIOC.all = ECanbRegs.CANTIOC.all;
ECanbShadow.CANTIOC.bit.TXFUNC = 1;
ECanbRegs.CANTIOC.all = ECanbShadow.CANTIOC.all;

ECanbShadow.CANRIOC.all = ECanbRegs.CANRIOC.all;
ECanbShadow.CANRIOC.bit.RXFUNC = 1;
ECanbRegs.CANRIOC.all = ECanbShadow.CANRIOC.all;
EDIS;

// Configure the eCAN for self test mode
   // Enable the enhanced features of the eCAN.
EALLOW;
ECanbShadow.CANMC.all = ECanbRegs.CANMC.all;
ECanbShadow.CANMC.bit.STM = 0; // Configure CAN for self-test mode
ECanbShadow.CANMC.bit.SCB = 1; // eCAN mode (reqd to access 32 mailboxes)
ECanbRegs.CANMC.all = ECanbShadow.CANMC.all;
EDIS;

   EALLOW;
      GpioCtrlRegs.GPAMUX1.bit.GPIO0 = 0; // GPIO0 = GPIO0
      GpioCtrlRegs.GPADIR.bit.GPIO0 = 1;
      EDIS;

      ECanaRegs.CANTRR.all= 0xFFFFFFFF;
      ECanaRegs.CANTA.all= 0xFFFFFFFF;

// Disable all Mailboxes
ECanbRegs.CANME.all = 0;

   EALLOW;
   ECanbShadow.CANMC.all = ECanbRegs.CANMC.all;
   ECanbShadow.CANMC.bit.CDR=1;
   ECanbRegs.CANMC.all = ECanbShadow.CANMC.all;
   EDIS;

//ÉèÖÃ·¢ËÍÓÊÏäID  À©Õ¹Ö¡
ECanbMboxes.MBOX0.MSGID.all = 0x00000000;

// Write to the MSGID field of RECEIVE mailboxes MBOX16
ECanbMboxes.MBOX16.MSGID.all = 0x9555AAA0;

/* // Configure Mailboxes 0-15 as Tx, 16-31 as Rx
// Since this write is to the entire register (instead of a bit
// field) a shadow register is not required.
ECanbRegs.CANMD.all = 0xFFFF0000;
*/
//ÓÊÏä0ÎªTX
ECanbShadow.CANMD.all = ECanbRegs.CANMD.all;
ECanbShadow.CANMD.bit.MD0 =0;
ECanbShadow.CANMD.bit.MD16 =1;
ECanbRegs.CANMD.all = ECanbShadow.CANMD.all;

/*  // Enable all Mailboxes
// Since this write is to the entire register (instead of a bit
// field) a shadow register is not required.
ECanbRegs.CANME.all = 0xFFFFFFFF;
*/

// Specify that 8 bits will be sent/received
ECanbMboxes.MBOX0.MSGCTRL.bit.DLC = 8;

// No remote frame is requested Ã»ÓÐÔ¶·½Ó¦´ðÖ¡
// Since RTR bit is undefined upon reset,
// it must be initialized to the proper value
ECanbMboxes.MBOX0.MSGCTRL.bit.RTR = 0;

// Write to the mailbox RAM field of MBOX0
ECanbMboxes.MBOX0.MDL.all = 0x01010101;
ECanbMboxes.MBOX0.MDH.all = 0x01010101;

EALLOW;
ECanbShadow.CANMC.all = ECanbRegs.CANMC.all;
ECanbShadow.CANMC.bit.CDR = 0;
ECanbRegs.CANMC.all = ECanbShadow.CANMC.all;
EDIS;

   //ÓÊÏäÊ¹ÄÜMailbox0 16
   ECanbShadow.CANME.all = ECanbRegs.CANME.all;
   ECanbShadow.CANME.bit.ME0 =1;
   ECanbShadow.CANME.bit.ME16 =1;
   ECanbRegs.CANME.all = ECanbShadow.CANME.all;

// Since this write is to the entire register (instead of a bit
// field) a shadow register is not required.
EALLOW;
ECanbRegs.CANMIM.all = 0xFFFFFFFF;//Ê¹ÄÜÓÊÏäÖÐ¶Ï

// Request permission to change the configuration registers
ECanbShadow.CANMC.all = ECanbRegs.CANMC.all;
ECanbShadow.CANMC.bit.CCR = 1;
ECanbRegs.CANMC.all = ECanbShadow.CANMC.all;
EDIS;

// Wait until the CPU has been granted permission to change the
// configuration registers
// Wait for CCE bit to be set..
do
{
   ECanbShadow.CANES.all = ECanbRegs.CANES.all;
} while(ECanbShadow.CANES.bit.CCE != 1 );

// Configure the eCAN timing
EALLOW;
ECanbShadow.CANBTC.all = ECanbRegs.CANBTC.all;

ECanbShadow.CANBTC.bit.BRPREG = 9; // (BRPREG + 1) = 10 feeds a 15 MHz CAN clock
ECanbShadow.CANBTC.bit.TSEG2REG = 5 ; // to the CAN module. (150 / 10 = 15)  5 7
ECanbShadow.CANBTC.bit.TSEG1REG = 7;  // Bit time = 15                   7 15
ECanbRegs.CANBTC.all = ECanbShadow.CANBTC.all;//1Mbps  600

ECanbShadow.CANMC.all = ECanbRegs.CANMC.all;
ECanbShadow.CANMC.bit.CCR = 0;
ECanbRegs.CANMC.all = ECanbShadow.CANMC.all;
EDIS;

// Wait until the CPU no longer has permission to change the
// configuration registers
do
{
   ECanbShadow.CANES.all = ECanbRegs.CANES.all;
} while(ECanbShadow.CANES.bit.CCE != 0 );

// Begin transmitting
for(;;)
{

LED1 = 1;
for(j=0;j<1000;j++)
   for(k=0;k<1000;k++);
LED1 = 0;
for(j=0;j<1000;j++)
   for(k=0;k<1000;k++);
// DELAY_US(500);

   ECanbRegs.CANTRS.all = 0x00000001;  // Set TRS for all transmit mailboxes
//    while(ECanbRegs.CANTA.all == 0x0000FFFF ) {}  // Wait for all TAn bits to be set..
   while(ECanbRegs.CANTA.all == 0){}
   ECanbRegs.CANTA.all = 0x00000001; // Clear Mailbox0 TAn

   MessageSendCount++;
//    MessageReceivedCount++;

   ECanbMboxes.MBOX0.MDL.all = 0x01010101;
   ECanbMboxes.MBOX0.MDH.all = 0x01010101;
｝
｝

只看该作者 · 2013-12-10 21:40

现象为，灯闪一下后，不再亮了，用示波器连CAN高和CAN低，有矩形波····

3万 · 2013-12-10 22:10

没看明白楼主用的什么单片机

只看该作者 · 2013-12-13 20:15

dirtwillfly 发表于 2013-12-10 22:10
没看明白楼主用的什么单片机

额···不好意思，用的是DSP。不过找到原因了，是因为没有外接接收的CAN节点，所以没有应答，故认为没有发送成功，因此没有置位TA。
不过又有新问题了，DSP28335的eCAN收发器用的是VP230，CAN_L和CAN_H对GND为什么都是负电平？这是正常的吗？
而且，为隐形电平的时候，CAN_L=CAN_H=-1.5V，为显性电平时，CAN_H-CAN_L差值为1.3左右，不是应该差值大于2V吗？

只看该作者 · 2016-8-23 14:32

楼主，问题解决了吗

DSPCAN总线发送程序，为什么发送数据后TA没有被置位？

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