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efim
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5 sign-ins First reply posted First question asked

We are using TLE7259-3 LIN Transceiver in Flash Mode. Due interrupts it is not always possible to get exact timing of switching sequence to switch to Flash Mode.

Is there a possibility to recognize to which mode the LIN Transceiver switched i.e. similar to NXP MC33662?

Or has Infineon an other LIN Trasceiver supported this feature?

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Albab_A
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5 likes given 50 solutions authored 100 replies posted

Hello,

Maybe if you can check in your code and see what is the reason for the interrupt event. It must not be from the LIN Side. However, in order to differentiate what would be the LIN Mode. It is for sure that LIN will be either in Normal Mode or Flash Mode.  You can differentiate it  by the slew rate control of the LIN Bus signal . Under Normal Mode data transmission is around 20 kbps and in Flash Mode it can go as high as 100 kbps because slew mode control mechanism at output is disabled under LIN Flash Mode.

 

Best Regards,

Albab

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Albab_A
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5 likes given 50 solutions authored 100 replies posted

Hello,

What do you mean by "exact timing of switching sequence". Can you please elaborate this point in order to better understand the issue.

As per the Datasheet The TLE7259-3 can be set to Flash mode only from Normal Slope mode . Flash mode is entered
by setting the EN pin to “Low” for the time tfl1 and generating a falling and a rising edge at the TxD pin with the
timing tfl2, tfl3 and tfl4 . Leaving the Flash mode by the same sequence, sets the TLE7259-3 back to
Normal Slope mode. Finally to release the data transmission it is required to set the TxD pin to “High” for the time
tto,rec.

AliAl_0-1701777485406.png

Regarding the transceiver state you can always refer to state diagram as below, but you have to make sure that transition is within the guidelines.

AliAl_1-1701777579915.png

 

 

 

Best Regards,

Albab

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efim
Level 1
Level 1
5 sign-ins First reply posted First question asked

Hello AliAl,

the device set Transceiver to Flash mode by software and uses sequence described in your reply. In the Table 6 page 20 of datasheet you can see the typical sequence time of 35µs. and other timing values for this sequence. 

Due to an interrupt sometimes occur during the sequence this timing not always fulfilled. In this case LIN transceiver not set to Flash mode and sequence must be repeated. To do this I need to know the mode of transceiver after the sequence. Does transceiver successfully entered Flash mode or not.

 

Best Regards,

Efim

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Albab_A
Moderator
Moderator
Moderator
5 likes given 50 solutions authored 100 replies posted

Hello,

Maybe if you can check in your code and see what is the reason for the interrupt event. It must not be from the LIN Side. However, in order to differentiate what would be the LIN Mode. It is for sure that LIN will be either in Normal Mode or Flash Mode.  You can differentiate it  by the slew rate control of the LIN Bus signal . Under Normal Mode data transmission is around 20 kbps and in Flash Mode it can go as high as 100 kbps because slew mode control mechanism at output is disabled under LIN Flash Mode.

 

Best Regards,

Albab

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efim
Level 1
Level 1
5 sign-ins First reply posted First question asked

Hello Albab,

yes the Interrupt is not from LIN, but device needs them.

Do Infineon has a paper how to measure slew rate on the LIN bus for this propose? The device is a LIN master node and we don't know how do LIN slave nodes react to the wrong  baud rate. Also if a LIN slave node send wakeup signal to LIN during slew rate measurement it destroy the Flash Mode recognition. The same problem occurs if the LIN slave node need to switch to Flash Mode at the same time and recognizes the Flash Mode the same way.

 

Best Regards,

Efim

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Albab_A
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5 likes given 50 solutions authored 100 replies posted

Hi,

Unfortunately, No. This document is not available. As you mentioned due to interrupt you were not able to follow the switching sequence across EN, TxD to enter Flash Mode. This surely mean that currently LIN will be in Normal Mode. And same goes for Flash to Normal transition.

 

Thanks.

Albab

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efim
Level 1
Level 1
5 sign-ins First reply posted First question asked

Hi,

yes it is sometimes. Therefore I need a possibility to recognize LIN transceiver Mode after switching sequence. What do developers say about this?

Best Regards,

Efim

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Albab_A
Moderator
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5 likes given 50 solutions authored 100 replies posted

Hello,

Apart from the uC code change. Other way to validate whether the LIN has entered the Flash Mode or not  from LIN Tx end-

1. Check bit rate in the LIN Analyser and compare it with what was shown in Normal Mode.

2. Check from uC GUI what is the bit rate because the bit rate there has to be in sync with that of controller or Analyser.

 

Best Regards,

Albab

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