XMC4500 USIC App Note misleading documentation

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cross mob
Not applicable
Hello,

I'm writing this thread to call attention to something which I feel is very misleading in the USIC application note.

On page 17, the note specifically states:

1278.attach

In my opinion this is really ambiguous. The correct behavior is to simultaneously write a value to the DPTR field and 0 to the SIZE field (atomically), but the writing implies that one should first write a 0 to the SIZE field and only AFTER that should one write to the DPTR field. This ambiguity took me forever to figure out and I really wish it was specified more clearly. In order to figure out the correct behavior I had to look at the DAVE generated code.

--J
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4 Replies
Travis
Employee
Employee
First solution authored Welcome! 500 replies posted
Hi jsharf,

Thanks for pointing out. We shall review this point.

Best Regards
Travis
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SunYajun
Employee
Employee
10 replies posted 5 replies posted Welcome!
Detailed information about FIFO initialization sequence:
- It is recommended to initialize FIFO structure using write value to DPTR and SIZE in one write cycle in application SW.
- When writing DPTR while SIZE = 0, both pointer is updated and the buffer is considered as empty.
- A write access to DPTR while SIZE>0 can’t modify pointer and it will be ignored, also following code must be avoided in FIFO initialization .
TBCTR/RBCTR <= SIZE value
TBCTR/RBCTR <= pointer value
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Travis
Employee
Employee
First solution authored Welcome! 500 replies posted
Hi Jsharf,

We shall make the necessary changes in the next version release. Thanks for point out.

Best regards
Travis
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Not applicable
Hi Jsharf,

You're right! I also think about it when reading the document.

@Travis: Thanks for notation 🙂
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