PIC18F25K80 CAN传统模式：可疑的偶然发射

嗨，罗宾，请你分享一下你的密码好吗？在传统模式下发送消息：测试缓冲区的txReq是否被清除。如果TXREQ被清除，则用值填充TX缓冲区ID和数据寄存器。将TXReq设置为“1”，以便将消息排队进行传输。请注意，TXReq只是一个发送请求位。设置此位意味着相应的传输缓冲器有待传输的消息。这并不保证消息在比特被设置之后立即被发送。“何时发送消息”的问题是基于发送优先级的。这取决于每个缓冲区的txReq位的轮询顺序。这里有一个例子说明了它是如何完成的：上面的代码片段是ECC遗留模式的MCC生成代码的一个例子。K80 ECAN已经在MCC中得到支持，我建议您使用这个工具来生成ECAN API和驱动程序。谢谢，Tam。



      以下为原文

    Hi Robin,
 
Can you share your code please?
 
To transmit a message in legacy mode:

• Test if the buffer's TXREQ is cleared.
  
• If TXREQ is cleared, populate the TX buffer ID and data registers with values.
  
• Set the TXREQ to '1' to queue the message for transmission.
  

Note that TXREQ is only a transmit request bit. Setting this bit means the corresponding transmit buffer has a message pending for transmission. This does not guarantee that the message will be instantaneously transmitted after the bit is set.
 
The question of "when the message would be transmitted" is based on the transmit priority. This depends on the order of polling of your TXREQ bits for each buffer. Here's an example of how it's done:
 
uint8_t CAN_transmit(uCAN_MSG *tempCanMsg)
{
uint8_t tempEIDH = 0;
uint8_t tempEIDL = 0;
uint8_t tempSIDH = 0;
uint8_t tempSIDL = 0;
uint8_t returnValue = 0;

if (TXB0CONbits.TXREQ != 1)
{
convertCANid2Reg(tempCanMsg->frame.id, tempCanMsg->frame.idType, &tempEIDH, &tempEIDL, &tempSIDH, &tempSIDL);

TXB0EIDH = tempEIDH;
TXB0EIDL = tempEIDL;
TXB0SIDH = tempSIDH;
TXB0SIDL = tempSIDL;
TXB0DLC = tempCanMsg->frame.dlc;
TXB0D0 = tempCanMsg->frame.data0;
TXB0D1 = tempCanMsg->frame.data1;
TXB0D2 = tempCanMsg->frame.data2;
TXB0D3 = tempCanMsg->frame.data3;
TXB0D4 = tempCanMsg->frame.data4;
TXB0D5 = tempCanMsg->frame.data5;
TXB0D6 = tempCanMsg->frame.data6;
TXB0D7 = tempCanMsg->frame.data7;

TXB0CONbits.TXREQ = 1; //Set the buffer to transmit
returnValue = 1;

}
else if (TXB1CONbits.TXREQ != 1)
{

convertCANid2Reg(tempCanMsg->frame.id, tempCanMsg->frame.idType, &tempEIDH, &tempEIDL, &tempSIDH, &tempSIDL);

TXB1EIDH = tempEIDH;
TXB1EIDL = tempEIDL;
TXB1SIDH = tempSIDH;
TXB1SIDL = tempSIDL;
TXB1DLC = tempCanMsg->frame.dlc;
TXB1D0 = tempCanMsg->frame.data0;
TXB1D1 = tempCanMsg->frame.data1;
TXB1D2 = tempCanMsg->frame.data2;
TXB1D3 = tempCanMsg->frame.data3;
TXB1D4 = tempCanMsg->frame.data4;
TXB1D5 = tempCanMsg->frame.data5;
TXB1D6 = tempCanMsg->frame.data6;
TXB1D7 = tempCanMsg->frame.data7;

TXB1CONbits.TXREQ = 1; //Set the buffer to transmit
returnValue = 1;
}
else if (TXB2CONbits.TXREQ != 1)
{

convertCANid2Reg(tempCanMsg->frame.id, tempCanMsg->frame.idType, &tempEIDH, &tempEIDL, &tempSIDH, &tempSIDL);

TXB2EIDH = tempEIDH;
TXB2EIDL = tempEIDL;
TXB2SIDH = tempSIDH;
TXB2SIDL = tempSIDL;
TXB2DLC = tempCanMsg->frame.dlc;
TXB2D0 = tempCanMsg->frame.data0;
TXB2D1 = tempCanMsg->frame.data1;
TXB2D2 = tempCanMsg->frame.data2;
TXB2D3 = tempCanMsg->frame.data3;
TXB2D4 = tempCanMsg->frame.data4;
TXB2D5 = tempCanMsg->frame.data5;
TXB2D6 = tempCanMsg->frame.data6;
TXB2D7 = tempCanMsg->frame.data7;

TXB2CONbits.TXREQ = 1; //Set the buffer to transmit
returnValue = 1;
}
return (returnValue);
}
 
The snippet above is an example of MCC-generated code for ECAN legacy mode. The K80 ECAN is already supported in MCC and I suggest you use this tool to generate your ECAN APIs and drivers.
 
Thanks,
Tam