TCAN4551-Q1: Interesting fields missing from Interrupts register 0x0820

Ed Goldstein

Part Number: TCAN4551-Q1
Other Parts Discussed in Thread: TCAN4550

I notice in the demonstration software in the structure TCAN4x5x_Device_Interrupts, there are a number of diagnostic flags that can highlight CAN hardware problems, such as:

uint8_t CBF : 1;

uint8_t CANBUSBAT : 1;
uint8_t CANBUSGND : 1;
uint8_t CANBUSOPEN : 1;
uint8_t CANLGND : 1;
uint8_t CANHBAT : 1;
uint8_t CANHCANL : 1;
uint8_t CANBUSTERMOPEN : 1;

However, these are all reserved in the data sheet.

Are they no longer supported?

Are there any guides on what flags are available to perform bus error diagnostics and recovery?

Thanks.

over 5 years ago

0 Ed Goldstein over 5 years ago

Prodigy 90 points

Further to this, CANTO is mentioned in the data sheet on page 55, but it is not in the register or Interrupts Field Descriptions. Has it been renamed to CANSLNT? or is that something different?

+1 Eric Hackett over 5 years ago in reply to Ed Goldstein

TI__Guru 74922 points

Ed,

Thanks for pointing this out in our code, those functions were removed from the final released version of the device. Those definitions are leftover from an earlier version of the device where they were included and we were using the code internally to test the device.

In terms of diagnostic features in the registers, registers 0x0820 are the general CAN diagnostic flags, and 0x0824 are the MCAN interrupts for CAN controller messaging and protocol.

Can you let me know which datasheet you are looking at? I can't find the CANTO mention on page 55 in the online datasheet I'm reading. CANSLNT is a flag that is asserted when the CAN bus has no activity for longer tSILENCE parameter.

Regards,

Eric Hackett

0 Ed Goldstein over 5 years ago

Prodigy 90 points

Hi Eric,

The document is the pdf currently at https://www.ti.com/product/TCAN4551-Q1?qgpn=tcan4551-q1#support-training : https://www.ti.com/lit/ds/symlink/tcan4551-q1.pdf?ts=1620798778892&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTCAN4551-Q1

Middle of page 55. after table 18.

CANTO: CAN Timeout: flag indicates a CAN bus timeout event while in Standby mode with frame detection
enabled. If there is no activity on the CAN bus for more than tSILENCE while in Standby mode with frame detect
enabled, this flag is set.

It's a shame about those other signals being withdrawn. They would have been very helpful to diagnose CAN connection problems remotely. I suppose these signals were withdrawn because they were not reliable.

Kind regards,

Ed.

0 Eric Schott1 over 5 years ago in reply to Ed Goldstein

TI__Guru 53535 points

Hi Ed,

If it's perhaps worth including on a separate node or in conjunction with TCAN4550, the bus fault diagnostic feature is included on TCAN1144 and TCAN1146. Let me know if you have any questions on these devices.

Regards,
Eric Schott

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TCAN4551-Q1: Interesting fields missing from Interrupts register 0x0820