Re: Visit

Hello Kees

The keyword here is "can" be implemented in
the driver. Most of the time it is not.

For example on the NXP Freescale S12 the driver you
get with the paid Code Warrior does not have a
priority queue, while the free driver you can
download from the website, I assume this one
is a bit more recent, has  a priority queue.

Simon

Simon Byholm - Software Manager / Quality Manager

Phone: +358 6 357 6306
Fax: +358 6 357 6320
email: [email protected]
web: www.tke.fi

TK Engineering solves your CAN, CANopen, J1939 and NMEA2000 problems by providing the hardware, software and know-how you need to design, manufacture and troubleshoot your industrial and heavy machine CAN networks. Call +358 6 357 6300 or email [email protected] to learn how we can help you solve your CAN related problems.

On 21.11.2016 10:18, Kees Zagers wrote:
> Tx priority.
> This can be achieved by defining multiple FIFO's with different
> priorities. The CAN controller in the Microchip PIC32 has this done in
> hardware. Up to 32 FIFO's with flexible depth of 1 to 32 messages can be
> defined as either Rx or Tx FIFO. The Tx FIFO's have 4 levels of priority.
> If the CAN controller does not have an internal Tx FIFO, this mechanism
> can be implemented in the driver.
>
> Kees
>
> Op 19-11-2016 om 20:12 schreef Simon Byholm:
>> Hello John
>>
>> One thing I've noticed is that CAN driver implementations usually
>> use a fifo style send buffer, letting low priority messages block the
>> queue, when there's a higher priority message that should really
>> be sent first.
>>
>> Some discussion on this would probably be useful.
>>
>> Simon
>>
>> Simon Byholm - Software Manager / Quality Manager
>>
>> Phone: +358 6 357 6306
>> Fax: +358 6 357 6320
>> email:[email protected]
>> web:www.tke.fi
>>
>> TK Engineering solves your CAN, CANopen, J1939 and NMEA2000 problems by providing the hardware, software and know-how you need to design, manufacture and troubleshoot your industrial and heavy machine CAN networks. Call +358 6 357 6300 or [email protected]  to learn how we can help you solve your CAN related problems.
>> On 19.11.2016 11:46, John Dammeyer wrote:
>>>
>>> Hi everyone,
>>>
>>> I know this isnÂ’t directly CAN bus related but I had the pleasure of 
>>> a visit with Lars-Berno Fredriksson from KVASER today.Been a few 
>>> years since I met him.Got caught up on all the CAN and CANFD things 
>>> that his company is doing.
>>>
>>> As we discussed the olden days when even CAN drivers werenÂ’t 
>>> available yet, I realized how much I missed the detailed discussions 
>>> on the working of the CAN bus.ItÂ’s true though, there are many 
>>> experts out there now who have lots of experience and the internet 
>>> is full of reference information that wasnÂ’t around 20 years 
>>> ago.Companies like Microchip have their own forums and often people 
>>> interested in the CAN bus never even make it to this list.
>>>
>>> Browsing through some of the messages from the comp.arch.embedded 
>>> UseGroup in 1995, the names of the contributors are Ken Tindell, 
>>> Edwin Armstrong, Olaf Pfeiffer, Stephen Pelc and there is a rich 
>>> amount of information about CAN.Ken Tindell started this list that 
>>> was eventually and is now graciously supported and maintained by Vector.
>>>
>>> IÂ’ve been asked a number of times to put my experience down into 
>>> either a book or a series of essays on CAN bus.IÂ’ve been fortunate 
>>> enough to have had a set of interesting experiences.Even to being on 
>>> a team developing and extension of the CAN bus to run on powerline 
>>> and deliver Ethernet Connectivity with up to 4K byte packets between 
>>> the arbitration and the CRC.In many ways CAN FD is a subset of that 
>>> original design.
>>>
>>> Anyway, IÂ’d like to get some feedback on what might be interesting 
>>> in a book or a series of essays.ThereÂ’s already lots on the low 
>>> level stuff.Less on High Level Protocols and whatÂ’s there is often 
>>> deep into the details.Maybe more implementation examples and how 
>>> itÂ’s done?
>>>
>>> So the floor is open.LetÂ’s have a discussion on what isnÂ’t well 
>>> documented.
>>>
>>> Thanks
>>>
>>> John Dammeyer
>>>
>>> "ELS! Nothing else works as well for your Lathe"
>>>
>>> Automation Artisans Inc.
>>>
>>> http://www.autoartisans.com/ELS/
>>>
>>> Ph. 1 250 544 4950
>>>
>>
>
> -- 
> Kees Zagers
> SI-Kwadraat B.V.
> Gulberg 31
> 5674 TE  NUENEN