UJA1076 Wake-up Sequence (Signal)

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

UJA1076 Wake-up Sequence (Signal)

Jump to solution
2,258 Views
maximillion
Contributor II

I am using UJA 1076 and I put it to sleep mode. So I need wake-up sequence remotely.

According to the application note attached below, how should the wake-up message be?

What should the message ID of the CAN message be?

Should the time between frames be 0.5 - 3 us?

Is the message to be sent [0x01,0x00.0x01,0x00] without message ID?

Ekran görüntüsü 2023-07-06 100300.png

0 Kudos
Reply
1 Solution
2,045 Views
JozefKozon
NXP TechSupport
NXP TechSupport

Dear Ufuk,

I didn't mean to send a CAN wake-up message to the UJA1076A. You have more devices on the CAN bus at the same time. While the UJA1076A is in Sleep mode and you communicate with other devices on the CAN bus, the UJA1076A unwantedly wakes-up. Is that correct? To wake-up the UJA1076A (willingly or unwillingly) you don't need to send any request. Just the pattern in the Figure 9. must appear on the CANH and CANL pins. 

JozefKozon_0-1691390634237.png

With Best Regards,

Jozef

 

View solution in original post

0 Kudos
Reply
9 Replies
2,241 Views
JozefKozon
NXP TechSupport
NXP TechSupport

Dear Ufuk,

the whole wake-up recessive-dominant-recessive-dominant sequence occurred on the CAN bus must be shorter, than the tto(wake) time. 

Screenshot_2.png

At the same time, the recessive and dominant times must be minimally twake(busrec)min and twake(busdom)min respectively. 

JozefKozon_0-1688716818790.png

Its best if you take the tto(wake) minimum value, 400us and the twake(busrec)min and twake(busdom)min maximum values. For both 3us. Even in this case you have plenty of time to conduct the wake-up recessive-dominant-recessive-dominant sequence within the tto(wake)=400us. 4*3us=12us.

Screenshot_3.png

The times between the recessive and dominant pulses is not stated.

Wtih Best Regards,

Jozef

0 Kudos
Reply
2,234 Views
maximillion
Contributor II

Dear Jozef, 

Firstly, I need to use the bitrate to time segments feature in the flexcan module to adjust the times you specify, right? 

According to what you wrote, no message IDs can be used, right?

Also, SBC woke up with CAN messages I sent randomly yesterday. Shouldn't it just wake up with recessive dominant recessive dominant sequences? Is this issue normal? 

Thanks for answering.

 

0 Kudos
Reply
2,225 Views
JozefKozon
NXP TechSupport
NXP TechSupport

Dear Ufuk,

you can disable the Bus wake-up detection with setting the STBCC bit to 0. If the STBCC is set to one, the recessive-dominant-recessive-dominant sequence will wake up the UJA1076. Yes, no message ID is required. 

When the UJA1076 woke-up with a random CAN message, can you please check if the message didn't contain the recessive-dominant-recessive-dominant sequence?

For example:

JozefKozon_0-1688726431685.png

Or any other timing, but the recessive-dominant-recessive-dominant sequence within the 400us.

With Best Regards,

Jozef

0 Kudos
Reply
2,187 Views
maximillion
Contributor II

Dear Jozef,

I checked the CAN message. I have tried to two can messages which contain wake-up sequence and without wake-up sequence but SBC always wake-up.
Also, I need remote wake-up mechanism so I must not disable wake-up remotely.

0 Kudos
Reply
2,172 Views
JozefKozon
NXP TechSupport
NXP TechSupport

Dear Ufuk,

please confirm, that you are using the newer UJA1076A. There is also an obsolete UJA1076. Please check the top marking.

Could you please connect the oscilloscope to the CAN bus, when you are sending the random message which wakes up the SBC? And please share the scope. I would like to to check if the message doesn't contain the BUS wake-up pattern.

With Best Regards,

Jozef

0 Kudos
Reply
2,081 Views
maximillion
Contributor II

Dear @JozefKozon,

Firstly, Sorry for getting back to your reply late.

I have UJA1076A High-speed CAN core system basis chip. I'm not sure the wake up message was sent correctly.

I attached screenshot please check it.

ss1.png

 

ss2.png

0 Kudos
Reply
2,057 Views
JozefKozon
NXP TechSupport
NXP TechSupport

Dear Ufuk,

thank you for the scope. However this doesn't seem to be taken from the CANH and CANL differential pair pins. Is the signal taken from TXDC or RXDC pin? Could you please connect two probes on the CANH and CANL pins while the UJA1076A is in Sleep mode and please share a scope of pattern, which unwantedly woken-up the SBC?

JozefKozon_0-1691385567770.png

The wake-up pattern doesn't need to contain the CAN ID, DATA, nor CRC value. Any pattern on the CANH and CANL pins will wake-up the SBC as long as it fulfills the CAN wake-up timing diagram in the Figure 9. 

JozefKozon_1-1691385881219.png

With Best Regards,

Jozef

 

0 Kudos
Reply
2,050 Views
maximillion
Contributor II
Dear Jozef,

Signal received from TXDC I will share pattern of wake up for CANH and CANL as soon as possible.
I am using S32K148evb to send wake-up pattern message. I am not sure how to send can wake-up message without message ID or DATA. According to your information should I send only 0x0A
0 Kudos
Reply
2,046 Views
JozefKozon
NXP TechSupport
NXP TechSupport

Dear Ufuk,

I didn't mean to send a CAN wake-up message to the UJA1076A. You have more devices on the CAN bus at the same time. While the UJA1076A is in Sleep mode and you communicate with other devices on the CAN bus, the UJA1076A unwantedly wakes-up. Is that correct? To wake-up the UJA1076A (willingly or unwillingly) you don't need to send any request. Just the pattern in the Figure 9. must appear on the CANH and CANL pins. 

JozefKozon_0-1691390634237.png

With Best Regards,

Jozef

 

0 Kudos
Reply