PCAN-PC/104-Plus driver problems on i7 computer

[Stuart]

I am having problems with getting PCAN-PC/104-Plus card working in an embedded computer. The computer has an Intel Core i7-620M CPU and Intel HM55 controller chipset. The initial testing was done in Win7-x64 with the lasted pc104plus.zip package from the support page. The driver installs ok and doesn't show any conflicts in the device manager. PCAN-View recognises the card and if I disconnect the card from the CAN bus I can send out properly formed messages (as seen on a digital scope). However, as soon I receive a valid message the PCAN-View "Overruns" field starts incrementing and I can't send any more messages until I stop the incoming message stream and reset the card in PCAN-View.

Initially, I thought it might be a problem with Win7-x64, so I tried Win7-x32 and had the same fault. Similarly, with RedHat x64 the test programs did not provide valid output even though the /proc/pcan interface showed that packets were received. I then tried different jumper positions for the device configuration. All jumper position had the same result, except position 3 which had an I/O conflict.

I then installed the card in a different machine with an Atom CPU and 945GSE/ICH7-M controller chipset with Win7-x32. In this setup the card worked fine. On closer inspection of the device manager details, the main difference between the two configurations was the memory location assigned to the driver. In the Atom computer the driver was assigned the memory resource areas of FEBE0000- FEBEFFFF & FEBF0000- FEBFFFFF; while for the i7 computer the memory resource areas were D5400000- D540FFFF & D5410000- D541FFFF. The same memory locations were used irrespective of the configuration jumper setting or whether the OS was x32 or x64.

Finally, I tested a PCAN-USB dongle on the i7 computer and it worked fine.

Any ideas on how to resolve this problem?

Thanks

Stuart

[M.Maidhof]

Hello,

when you get overruns with PCAN-View with a PCAN-PC/104-Plus card on that Intel Core i7-620M CPU, it looks like the IRQ settings on the card will not fit to your mainboard settings. So please check the BIOS and the used IRQ settings again, to solve that problem.

best regards

Michael

[Stuart]

I checked the i7's BIOS and IRQs are enabled for the PCI bus. I tried changing the jumper settings to move the position on the PCI bus and allocated IRQ but I continue to get overruns with PCAN-View. I checked with a scope and a different system and valid CAN packets are being received by the i7. Additionally, PCAN-View never shows that it received a valid CAN packet, it immediately starts to overrun.

I checked in Windows and while for each of the different jumper configurations the IRQ is shared with another device, these device are generally in-active (i.e. unused IDE bus) or low rate motherboard services.

Do you have any other suggestions?

[M.Maidhof]

Hi,

when PCAN-View shows an overrun immediately after start, it still looks like an IRQ problem. Do you have a real PC104plus system, or do you use an adapter on an normal PCI motherboard?

Which kind of IRQ does the devicemanager show up for that card? What kind of BIOS settings do you have to change the IRQ of the PC104-plus slot. Please also change the ID with the IRQ jumper for a test.

[Stuart]

I should clarify that the the PCAN-view overrun starts ~2s after a CAN slave starts to send its heartbeat message. If no device is on the CAN bus or the CAN slave hasn't started initialising then it won't overrun.

The computer is a Nuvo-1005S-620M with PCI-104 expansion bus. There are no options in the BIOS to change the PCI IRQ. In the BIOS I can make sure that the PCI-Express bus which the PCI bridge is attached to is enabled and adjust the PCI latency.

I have tried different ID/IRQ settings and I can see it change the device IRQ in Windows device manager but it makes no change. I have attached some screen shoots to show the settings.

[M.Maidhof]

Hi,

please contact the manufacturer of the CPU board, and ask for a BIOS update. We remember similar problems with our PC/104-plus cards on an other CPU board from an other manufacturer, which could be solved by changing the BIOS of the board. The problem looks like the IRQ from our board is not connected to the IRQ lines of the CPU, thats why the CAN-Controller will show an overrun, after some messages are on the bus, because our driver will not get the info about the IRQ from the mainboard/CPU.

best regards

Michael

[Stuart]

Hi Michael,

You were correct, the problem was with the i7 BIOS. After the i7 manufacturer sent us a BIOS update the PEAK PC/104-Plus card is now working.

Thanks for your help in diagnosing the problem.

Stuart