FlexCAN RX FIFO filter not accepting

[cpham2]

Evaluation board: MIMXRT1170-EVK

Spec: i.MX RT1170 Processor Reference Manual (document number: IMXRT1170RM Rev. 1, 05/2021)

I am facing an issue with RX FIFO CAN filter. I only care about extended ID bits 24 down to 21 to be zero.  I configure ID filter table elements 0 to 7 located at addresses: E0, E4, E8, EC, F0, F4, F8, FC to 0x4000_0000 and RXFGMASK to 0x01E0_0000. I send a test CAN message with ID 0x001F8001(bits 24:21 = 0).  I don’t get a match. However, if I change the RXFGMASK to 0x0, then I get a match. It does not matter if I set the other RXMGMASK, RX14MASK, RX15MASK and RXIMR[63:0] to 0x0 or 0xffff_ffff. According to the reference manual, section 66.3.8 Rx FIFO (page 5310), if MCR[IRMQ] = 0, then the FIFO filter is affected by RXFGMASK.  Below is the setup of the CAN configuration. I wonder if I miss any bit setup. Greatly appreciate your help. Thanks.

Regards,

Chau 

CAN controller configurations: MCR, CTRL2, ID filter table and mask registers.

MCR      0x20a2000f         RW         0x40c3c000        Module Configuration register

…

MCR[REFEN] = 1(enable RX fifo receive) bit 29th

MCR[IRMQ] = 0 (individual RX masking disable) bit 16

MCR[IDAM] = 0 (format A) bit(9:8)

MCR[MAXMB] = 0xf (16 MB configuration) bit(6:0)

…

CTRL2    0x00b10000        RW         0x40c3c034        Control 2 register

…

CTRL2[RFFN] = 0 (8 RX FIFO filter element)

CTRL2[MRP] = 0 (matching starts from RX FIFO and continues on mailboxes

…

According to the reference manual, section 66.3.8 Rx FIFO, if MCR[IRMQ] = 0, then the FIFO filter is affected by RXFGMASK. Any

RXMGMASK        0x00000000        RW         0x40c3c010        Rx Mailboxes Global Mask register

RX14MASK          0x00000000        RW         0x40c3c014        Rx 14 Mask register

RX15MASK          0x00000000        RW         0x40c3c018        Rx 15 Mask register

RXFGMASK          0x01e00000        RW         0x40c3c048        Rx FIFO Global Mask register

RXIMR[63:0]       0x00000000        RW         0x40c3c880        Rx Individual Mask registers

ID filter table: E0, E4, E8, EC, F0, F4, F8 and FC are configured to 0x4000_0000.

CS6        0x40000000        RW         0x40c3c0e0        Message Buffer 6 CS Register

MB1_64B_WORD4_L      0x40000000        RW         0x40c3c0e0        Message Buffer 1 WORD_64B Register

MB2_32B_WORD2_L      0x40000000        RW         0x40c3c0e0        Message Buffer 2 WORD_32B Register

MB4_16B_CS_L 0x40000000        RW         0x40c3c0e0        Message Buffer 4 CS Register

MB6_8B_CS        0x40000000        RW         0x40c3c0e0        Message Buffer 6 CS Register

ID6         0x40000000        RW         0x40c3c0e4        Message Buffer 6 ID Register

MB1_64B_WORD5_L      0x40000000        RW         0x40c3c0e4        Message Buffer 1 WORD_64B Register

MB2_32B_WORD3_L      0x40000000        RW         0x40c3c0e4        Message Buffer 2 WORD_32B Register

MB4_16B_ID_L  0x40000000        RW         0x40c3c0e4        Message Buffer 4 ID Register

MB6_8B_ID        0x40000000        RW         0x40c3c0e4        Message Buffer 6 ID Register

MB1_64B_WORD6_L      0x40000000        RW         0x40c3c0e8        Message Buffer 1 WORD_64B Register

MB2_32B_WORD4_L      0x40000000        RW         0x40c3c0e8        Message Buffer 2 WORD_32B Register

MB4_16B_WORD0_L      0x40000000        RW         0x40c3c0e8        Message Buffer 4 WORD_16B Register

MB6_8B_WORD0             0x40000000        RW         0x40c3c0e8        Message Buffer 6 WORD_8B Register

WORD06             0x40000000        RW         0x40c3c0e8        Message Buffer 6 WORD0 Register

MB1_64B_WORD7_L      0x40000000        RW         0x40c3c0ec         Message Buffer 1 WORD_64B Register

MB2_32B_WORD5_L      0x40000000        RW         0x40c3c0ec         Message Buffer 2 WORD_32B Register

MB4_16B_WORD1_L      0x40000000        RW         0x40c3c0ec         Message Buffer 4 WORD_16B Register

MB6_8B_WORD1             0x40000000        RW         0x40c3c0ec         Message Buffer 6 WORD_8B Register

WORD16             0x40000000        RW         0x40c3c0ec         Message Buffer 6 WORD1 Register

CS7        0x40000000        RW         0x40c3c0f0         Message Buffer 7 CS Register

MB1_64B_WORD8_L      0x40000000        RW         0x40c3c0f0         Message Buffer 1 WORD_64B Register

MB2_32B_WORD6_L      0x40000000        RW         0x40c3c0f0         Message Buffer 2 WORD_32B Register

MB4_16B_WORD2_L      0x40000000        RW         0x40c3c0f0         Message Buffer 4 WORD_16B Register

MB7_8B_CS        0x40000000        RW         0x40c3c0f0         Message Buffer 7 CS Register

ID7         0x40000000        RW         0x40c3c0f4         Message Buffer 7 ID Register

MB1_64B_WORD9_L      0x40000000        RW         0x40c3c0f4         Message Buffer 1 WORD_64B Register

MB2_32B_WORD7_L      0x40000000        RW         0x40c3c0f4         Message Buffer 2 WORD_32B Register

MB4_16B_WORD3_L      0x40000000        RW         0x40c3c0f4         Message Buffer 4 WORD_16B Register

MB7_8B_ID        0x40000000        RW         0x40c3c0f4         Message Buffer 7 ID Register

MB1_64B_WORD10_L    0x40000000        RW         0x40c3c0f8         Message Buffer 1 WORD_64B Register

MB3_32B_CS_L 0x40000000        RW         0x40c3c0f8         Message Buffer 3 CS Register

MB5_16B_CS_L 0x40000000        RW         0x40c3c0f8         Message Buffer 5 CS Register

MB7_8B_WORD0             0x40000000        RW         0x40c3c0f8         Message Buffer 7 WORD_8B Register

WORD07             0x40000000        RW         0x40c3c0f8         Message Buffer 7 WORD0 Register

MB1_64B_WORD11_L    0x40000000        RW         0x40c3c0fc          Message Buffer 1 WORD_64B Register

MB3_32B_ID_L  0x40000000        RW         0x40c3c0fc          Message Buffer 3 ID Register

MB5_16B_ID_L  0x40000000        RW         0x40c3c0fc          Message Buffer 5 ID Register

MB7_8B_WORD1             0x40000000        RW         0x40c3c0fc          Message Buffer 7 WORD_8B Register

WORD17             0x40000000        RW         0x40c3c0fc          Message Buffer 7 WORD1 Register

[Omar_Anguiano]

Hello
I hope you are well.

I'm checking your configuration to check if something is missing or if a field is not set correctly.

Best regards,
Omar