Tx and Rx not working for FlexCAN FD with BRS bit set

harshitanegandh — Wed, 14 Dec 2016 06:24:52 GMT

We are working on S32K144 EVB Q0100 board with CAN transreceiver UGA1169
1. Clock source is BUS clock with 56Mhz frequency and sampling point chosen is 75%
2. Rx_Fifo = false
3. Fd_Enable = true
4. /* Macros to Configure Tx message buffer */
#define CANTX_DATALENGTH 64u
#define CANTX_FDENABLE 1u
#define CANTX_FDPADDING 0u
#define CANTX_ENABLEBRS 1u
The above mentioned values are passed in the function "FLEXCAN_DRV_ConfigTxMb"

/* Macros to Configure Rx message buffer */
#define CANRX_DATALENGTH 64u
#define CANRX_FDENABLE 1u
#define CANRX_FDPADDING 0u
#define CANRX_ENABLEBRS 1u
The above mentioned values are passed in the function "FLEXCAN_DRV_ConfigRxMb"

5. /* Macros for CAN_Baudrate setting for (CAN0->CBT with 500Kbps nominal bit rate) */
#define BAUDRATE_PROPSEG 54u
#define BAUDRATE_PHASESEG1 27u
#define BAUDRATE_PHASESEG2 27u
#define BAUDRATE_PREDIVIDER 0u
#define BAUDRATE_RJUMPWIDTH 27u

/* Macros for CAN_FD_Baudrate setting for (CAN0->FDCBT with 2Mbps higher bit rate)*/
#define BAUDRATE_PROPSEGFD 6u
#define BAUDRATE_PHASESEG1FD 13u
#define BAUDRATE_PHASESEG2FD 6u
#define BAUDRATE_PREDIVIDERFD 0u
#define BAUDRATE_RJUMPWIDTHFD 6u

Am not able to transmit or receive with the above mentioned frequency.
Are these values correct for the given frequency?
Is this a valid range of frequency for this transreceiver?

Re: Tx and Rx not working for FlexCAN FD with BRS bit set

PetrS — Tue, 20 Dec 2016 13:35:50 GMT

Hi,

The UJA1169 is able to work up to 2Mbit for CAN FD.

It looks the timing setting is correct.

What if you decrease baudrate for data bit time? Does it work?

Also if BRS is cleared, are you able to transmit or receive frames?

BR, Petr

S32KのトピックTx and Rx not working for FlexCAN FD with BRS bit set

Tx and Rx not working for FlexCAN FD with BRS bit set

Re: Tx and Rx not working for FlexCAN FD with BRS bit set