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CAN transmission error in i.MX6D

Question asked by ko-hey on Dec 20, 2016
Latest reply on Jan 29, 2017 by ko-hey

Hi all

 

My customer have a trouble in CAN so I have a question about it.

Please tell me the following question.

 

// Symptom //

 

In CAN transmission, when the amount of data to be transmitted increases, erroneous data may be extra transmitted.

 

// Control Method //

 

The setting is as follow.

Using 54-63 message buffer for send.

LPRIO_EN = 1(Local Priority enabled)

LBUF = 0(Buffer with highest priority is transmitted first)

All PRIO = 0.

MCR AEN = 0(Abort disable).

IMASK = 0

 

 

They've controlled the following procedure for sending by 10 ms cycle.

1. Find a message buffer which CODE region is INACTIVE and ABORT.

2. Store the number of data, ID and data.

3. Write a "1100" to CODE then start sending.

 

Normally, all Message buffers are "INACTIVE" every 10 ms cycle, and the number of data is smaller than the message buffer number,

When the amount of data is large, the transmission process of the peripheral can not keep up, the message buffer is exhausted,

INACTIVE "will be sent repeatedly by looping in 1 and waiting tens of times to store the data.

At this time, occasionally, extra data may be transmitted.

 

 

// Question //

 

1.

When storing data to message buffer, is there a problem in the way of judging by looking at the CODE area as shown in 1 above ?

 

2.

Does IFLAG become 1 without setting with MASK?

 

According to p 1302, confirming transfer completion with IFLAG then confirming the result with CODE.

Also, in the description of IFLAG of p1349, it becomes 1 when transmission and reception succeed.

Is the interrupt generation different from the flag setting?

 

3.

In the explanation of p1315 abort, it is abort that the mechanism to safely interrupt pending.

I think that the pending is occurred when a data store to another high priority buffer during the arbitration is executed.

In that case, is there any risk of erroneous data transmission ?

 

In what situations does user need to take care the abort ?

 

Ko-hey

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