我使用的是MK24F12。我调整了Flexcan模块，使用Fleet Management Systems Interface从设备收集消息。 我打开RxFIFO并将ID接受模式设置为格式A.然后我用ID填充过滤表（它从第7个邮箱开始），并根据掩码使用RXIMR寄存器。其余的滤波器填充0x40000000，其余掩码寄存器填充0x5FFFFFFF。 当我开始听设备时，我会得到一些帧，但是这里的问题是我没有收到设备发送的所有消息，尽管它们匹配过滤器。 我知道，因为如果我将任何掩码寄存器设置为零，我将获得总线上的所有消息。 我注意到命中过滤器（RXFIR寄存器）是（0,1,4,5，...），换句话说，我得到的信息与存储在MailBox的寄存器CSn和IDn中的过滤器相匹配。
下面是日志，这里我添加了7个过滤器，我只有4种类型的消息。然后我删除了所有过滤器，你可以看到我跳过很多应该被捕获的消息。
[1.003] Filter added (Type: Ext, ID: 0x00FEE900, Mask: 0x00FFFF00)
[1.004] Filter added (Type: Ext, ID: 0x00FEFC00, Mask: 0x00FFFF00)
[1.005] Filter added (Type: Ext, ID: 0x00FEEE00, Mask: 0x00FFFF00)
[1.006] Filter added (Type: Ext, ID: 0x00FEC100, Mask: 0x00FFFF00)
[1.007] Filter added (Type: Ext, ID: 0x00F00400, Mask: 0x00FFFF00)
[1.008] Filter added (Type: Ext, ID: 0x00FEE500, Mask: 0x00FFFF00)
[1.008] Filter added (Type: Ext, ID: 0x00FEEA00, Mask: 0x00FFFF00)
[1.935] CAN.Got frame (Type: Ext, ID: 0x18F00420, Data: FF FF FF 80 0C FF FF FF, Filter: 4)
[2.436] CAN.Got frame (Type: Ext, ID: 0x18FEE520, Data: 58 1C 00 00 FF FF FF FF, Filter: 5)
[2.938] CAN.Got frame (Type: Ext, ID: 0x18FEE920, Data: FF FF FF FF 59 1C 00 00, Filter: 0)
[3.439] CAN.Got frame (Type: Ext, ID: 0x18FEFC20, Data: FF 48 FF FF FF FF FF FF, Filter: 1)
[4.944] CAN.Got frame (Type: Ext, ID: 0x18F00420, Data: FF FF FF C0 12 FF FF FF, Filter: 4)
[5.445] CAN.Got frame (Type: Ext, ID: 0x18FEE520, Data: 59 1C 00 00 FF FF FF FF, Filter: 5)
[6.950] CAN.Got frame (Type: Ext, ID: 0x18FEE920, Data: FF FF FF FF 5A 1C 00 00, Filter: 0)
[7.452] CAN.Got frame (Type: Ext, ID: 0x18FEFC20, Data: FF 46 FF FF FF FF FF FF, Filter: 1)
[8.957] CAN.Got frame (Type: Ext, ID: 0x18F00420, Data: FF FF FF 00 19 FF FF FF, Filter: 4)
[9.458] CAN.Got frame (Type: Ext, ID: 0x18FEE520, Data: 5A 1C 00 00 FF FF FF FF, Filter: 5)
at this point i removed all filters
[34.186] CAN.Got frame (Type: Ext, ID: 0x18F00420, Data: FF FF FF 00 4B FF FF FF, Filter: 0)
[34.688] CAN.Got frame (Type: Ext, ID: 0x18FEE520, Data: 62 1C 00 00 FF FF FF FF, Filter: 0)
[35.190] CAN.Got frame (Type: Ext, ID: 0x18FEE920, Data: FF FF FF FF 63 1C 00 00, Filter: 0)
[35.691] CAN.Got frame (Type: Ext, ID: 0x18FEFC20, Data: FF 34 FF FF FF FF FF FF, Filter: 0)
[36.193] CAN.Got frame (Type: Ext, ID: 0x18FEEE20, Data: 56 FF FF FF FF FF FF FF, Filter: 0)
[36.694] CAN.Got frame (Type: Ext, ID: 0x18FEC120, Data: AD 05 00 00 FF FF FF FF, Filter: 0)
[37.196] CAN.Got frame (Type: Ext, ID: 0x18F00420, Data: FF FF FF 40 51 FF FF FF, Filter: 0)
[37.698] CAN.Got frame (Type: Ext, ID: 0x18FEE520, Data: 63 1C 00 00 FF FF FF FF, Filter: 0)
[39.203] CAN.Got frame (Type: Ext, ID: 0x18FEE920, Data: FF FF FF FF 64 1C 00 00, Filter: 0)
[39.704] CAN.Got frame (Type: Ext, ID: 0x18FEFC20, Data: FF 32 FF FF FF FF FF FF, Filter: 0)
[40.206] CAN.Got frame (Type: Ext, ID: 0x18FEEE20, Data: 58 FF FF FF FF FF FF FF, Filter: 0)
[40.707] CAN.Got frame (Type: Ext, ID: 0x18FEC120, Data: AD 05 00 00 FF FF FF FF, Filter: 0)
答案 0 :(得分：0)
我发现我读取了MB的CS寄存器的CODE位，而对于过滤器2,3,6,7来说它是1 ......这意味着BUSY。但是如果FIFO引擎使用MB，它不包含CODE位，我们根本不应该检查消息缓冲区代码。 如果不使用某些位，它们可能会保持清晰。
问题已经结束。 这是MB and FIFO structure
的图片
