I use the K60 Flexcan to receive CAN messages. I use the RX Fifo. RFFN is set to 3, MB0..13 are part of the RX Fifo.
I can set the Filters to receive all messages. This works.
Now I want to use the filter mecahnism. I want to use the ID Filter table Format B. Individual filter are activated.
My problem:
All messages are receiving. Filterhit is 1.
I do not find detail information in case I use the Format B ID Table.
Which ID Filter works with which Indiviual mask?
Which entrie (combination) receive my messages and set the filterhit to 1.
My test setting (later I want to receive only specific IDs):
| /* compare all mask bits */ |
pCan->CTRL2 |= FLEXCAN_CTRL2_EACEN;
/* store RTR frames */
pCan->CTRL2 |= FLEXCAN_CTRL2_RRS;
/* Set Scan priority (RX Fifo first) */
pCan->CTRL2 &= ~FLEXCAN_CTRL2_MRP;
/* RX Fifo */
pCan->MCR |= FLEXCAN_MCR_FEN;
// RFFN is 3
pCan->CTRL2 = (pCan->CTRL2 & ~FLEXCAN_CTRL2_RFFN )
| (FLEXCAN_RFFN_VAL << FLEXCAN_CTRL2_RFFN_BIT_NO);
/* Set ID filter table format (RX Fifo mask - Format B / 01 ) */
pCan->MCR = (pCan->MCR & ~FLEXCAN_MCR_IDAM_MASK) | FLEXCAN_MCR_IDAM(1);
| /* Initialize mask registers - not relevant, I think */ |
pCan->RXMGMASK = 0x1FFFFFFFul;
pCan->RX14MASK = 0x1FFFFFFFul;
pCan->RX15MASK = 0x1FFFFFFFul;
//Test setting
// first should only receive, if bit 0 is set
// second only, if Bit1 is set
// next Bit 2 is set
// and so on
// the higher ID (RXIDB_0) should only receive 0x7FF - ignored for this test
| for(i = 0; i <= 13 ; i++) |
| { |
| | pCan->RXIMR[i] = 0xFFFF0000ul | (1ul<<i);// individual masks |
}
for(i = 0; i < (14-6)*4 ; i++)
{
| | FLEXCAN1_IDFLT_TAB(i) = 0x07FF07FFul; |
}
pCan->RXFGMASK = 0xFFFFFFFFul; //mask for all other IDs
