UJA1169ATK-F-3Z - CAN transceiver

[jiyeon]

Hello,

My team made a board with UJA1169ATK-F-3Z.

As I understood, Initially it is in "Forced Normal mode".

So If partial network will not be used, additional register setting using SPI doesn't necessary.

Just sending out data over TXD and RXD might be enough.

But stuff error occurs.

The source code works fine with previous CAN Transceiver.

Bit timing setting in MCU is like below.

MCAN_BitTimingParams gMcanBitTimingDefaultParams =
{
.nomRatePrescalar = 0x3U,
.nomTimeSeg1 = 0xFU,
.nomTimeSeg2 = 0x2U,
.nomSynchJumpWidth = 0x0U,
.dataRatePrescalar = 0x1U,
.dataTimeSeg1 = 0x5U,
.dataTimeSeg2 = 0x0U,
.dataSynchJumpWidth = 0x0U,
};

CANoe is configured 

- arbitration bit rate: 1000 kbps

- arbitration sampling point: 85%

- data bit rate: 5000 kbps

- data sampling point: 87.5%

How can I fix the problem?

Best regards, 

JIYEON.

[jiyeon]

Hi,

There were no signal in TXD/RXD.

Those two pin should be configured as Pull-up/Pull-down? Currently it is no pull.

Or would it be better to put some time delay before sending CAN message?

And I wish to check one more thing. In Forced Normal mode, WAKE pin should be Pulled-up/Pulled-down?

Thanks for your support.

BR, JIYEON.

[PetrS]

Hi,

there should be some signal on TXD if MCU is transmitting message, unless transceiver drives RXD low (so most probably is not active) and so MCUs CAN module is not "synchronized" to the bus. So check that.
If asking for pull option for UJA1169 TXD/RXD, then nothing is needed. TXD in input, internally pull-up towards V1 to ensure a safe defined recessive driver state in case the pin is left floating. RXD is an output.

For Wake-up pin; depending on the final application a pull-up resistor (for GND related input signals) or a pull down resistor (for BAT related input signals) might need to be added. See more in AH1306 Application hints document.

BR, Petr

In applications that do not use the local wake-up facility, local wake-up should be disabled
and the WAKE pin connected to GND.

[PetrS]

Hi,

yes, bit FNMC is factory preset to 1, so the UJA1169A initially boots up in Forced Normal mode and no SPI init is needed, CAN transceiver is active and you are able to send/receive messages.
You can inspect TXD/RXD and CAN line to know if correct message is seen.
It could be you will need to modify a bit timing little bit, depending on real signal, maybe decrease sample point. Also for this high rate you should have TDC enabled on CAN controller.

BR, Petr