TC36x how to send response using RX interrupt in ASCLIN slave mode.

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PaulY
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Hello,

I have questions about ASCLIN communication in TC36x. 

 

I want to send response to header of master node in slave mode for LIN communication using RX interrupt.

 

I configure to enable interrupt when EVB receives header from masternode by setting FLAGSENABLE.RHE bit.

 

actually the interrupt occurs when the EVB received header, but doesn't happend exactly.

 

I expected to happen interrupt after STOP bit of ID field in header frame, but interrupt is occured before STOP bit. 

 

so now, I implemented to send response function in RX interrupt service routine. Sometimes, It has frame error problem that response frame overlaps the end of header frames (overlaps stopbit of ID field). I checked this situation with a scope. 

 

I don't know what I am missing to configure. I want solution about this problem.

 

thanks.

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1 Solution
PaulY
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I clear this issue.

 

I configured early sample point position. 

oversampling factor = 15 / sample point position = 3

 -> change sample point position = 8 

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5 Replies
Di_W
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Please refer to 36.3.7.3 LIN Slave Sequences in user manual. If any question please feel free to ask.

PaulY
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Hello dw, thank you for your reply to me


I refered to 36.3.7.2 LIN Master Sequences in user manual. because I want to send response to the latest header. 

Can I use this sequence in RX interrupt service routine? After EVB receives header from master node, It has a RX interrupt and I implement user manual sequence in RX ISR 

but I dont know why response frame overlaps the end of header frame(exactly stopbit of ID Field) that is transmitted by master node.

 

So, I guess that RX interrupt is occured earlier than expected. and than EVB sends response before header frame end (stopbit)

 

PaulY_1-1678695446656.png

 - RX interrupt timing in id field of header frame

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Di_W
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Have you checked there is any settings about the delay after Stop Bit? I have not fully examined the part, please read the manual to look up the delay or something else?

PaulY
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Hello dw, 

I can't find delay parameter in this MCU. and I configure stopbit to 1 cuz LIN communication is neccesary 1 stopbit. 

I will also read more user manual to find about this situation to configure.

 

thank you.

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PaulY
Level 1
Level 1
5 sign-ins First like received First solution authored

I clear this issue.

 

I configured early sample point position. 

oversampling factor = 15 / sample point position = 3

 -> change sample point position = 8