Why would the BKGD port short to vcc when connecting USB ML-12E programmer?

[Sagetech]

Happened on three 9S12X processor over the last two weeks. Been using same method of programming and processor for years without issue

BKGD pulled up to 5v with 3.3k as is RESET.

Processor previously programmed fine, reconnecting programmer and can not recognize processor. Checking the BKGD pin it is shorted to VCC. Processor runs existing code fine, can not reprogram.

[saweddie]

Thanks for your reply.And I want to know which program should i use with usbdm to read data from hcs12 (s9s12G64)mcu?

[RadekS]

Hi Saw,

You may use any compatible debugger software.

I can recommend CodeWarrior for HCS12(X) IDE. The USBDM driver is directly included into CodeWarrior during USBDM driver installation. You may select TBDML as a target for USBDM driver.

You should install CodeWarrior for HCS12(X) IDE version 5.1 or 5.2(supported under Win10) and install an appropriate S12G64 service pack for CW5.1 (the same package may be applied also for CW 5.2 when you modify install path during installation).

See video how to download CW for HCS12(X) version 5.1 and appropriate patch.

https://community.nxp.com/videos/5109

I hope it helps you.

Best regards

Radek

[saweddie]

Can you recommend to me which programmer should I buy to reprogram S9S12G64 mcu via bkgd programming pin?

[RadekS]

Hi Saw,

The USB Multilink (=USB-ML12E) is now obsolete. The most frequently used tool is probably USB Multilink Universal (USB-ML-UNIVERSAL, sometimes called by shorter name UMultilink).

As low-cost solution, you may use debugger based on open source projects like OSBDM or USBDM. In such case, you may buy various types of debuggers. For example USBDMLT....

If you plan to produce small series and you require programming by push button, you should choose rather programmers like Cyclone Universal(it replaces obsolete Cyclone Pro programmer) or LFBDMPGMR...    

I hope it helps you.

Best regards

Radek

[RadekS]

Hi Tom,

there are several possible catastrophic scenarios why something like this happened, but most probable reason is that you or somebody else changed orientation of BDM cable.

Please check pin orientation on your board and additionally also at board inside USB BDM Multilink. It could be open by little bit violence at place where BDM cable leaves the Multilink box.

Typical orientation of first pin (red wire) is showed at attached picture.

I hope it helps you.

Have a great day,
RadekS

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[Sagetech]

Thank you for the reply.

Yes we have some products where it would be possible to install the connector backwards but on this particular set up that is not the case. It is a proven set up with keyed connectors. For example, we could program the device 10 times throughout the day and on the 11th time, we lose the port. Same programmer, same engineer, same setup, same process we have been doing for years!

[RadekS]

Hi Tom,

thank you for clarification.

In my previous post, I wanted point on fact that BDM cable could be connected wrongly also on Multilink side. Problem will be probably in something else.

So, you cannot connect to MCU randomly (1 from 10 attempts), or you cannot connect to MCU anymore (after 10 writes into MCU)?

In second case, it looks like potential issue with internal ESD diode. All pins (include BKGD pin) are protected against ESD charge by ESD diodes to power supply rail. ESD charge (or high voltage spike) could damage this diode and cause permanent short to VCC. This could be simply tested by temporary connecting resistor (1-5kOhm) between BKGD and GND pin. When it will work as voltage divider, MCU should be OK, and you could look root cause on programmer side.

Could you please place here (or send me) your schematic? USB BDM Multilink should have connected open collector at BKGD pin, therefore it should be independent on target power supply voltage range.

In first case, I would like to rather search issue in BDM interface.

Please check whether both LEDs on Multilink glow when you connect it into target board.

Idea: We know about some communication issues with particular versions of USB BDM Multilink revisions C. According PEmicro: ”We removed a few protection diodes in the new revision that we believe was causing communication issues. This should be component T3, T5, and T6.”

Please check your version of USB BDM Multilink and look whether PCB is assembled by T3, T5, and T6 components…

Idea: Since you use the same environment for years, it is possible that ribbon cable could be already secretly broken. Unfortunately durability of this part of hardware isn’t the best…

Could you please check wire connection of your ribbon cable?

Idea: Problem could be caused by USB connection or drivers. Do you use any USB hub between PC and Multilink? If yes, please try connecting Multilink directly into PC and try unplugging unnecessary USB peripherals. You can also try installing latest version of Multilink drivers:

P&E Hardware Interface Drivers, Version 11 (Win XP/Vista/7/8)

http://www.pemicro.com/downloads/download_file.cfm?download_id=301

P&E Hardware Interface Drivers Version 9 (Windows 98/ME)

http://www.pemicro.com/downloads/download_file.cfm?download_id=53

Idea: I already meet with issues during programming because of noise generated by currents which flows between GND potentials. Is it possible somehow improving grounding in your case (between PC GND and target board GND)?

I hope it helps you.

Have a great day,
RadekS

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[sonalchirme]

hi,

I am also facing same kind of problem with my new multilink universal programmer version C. 

All voltages on micro-controller boards are ok. when i am connecting BDM blue light turning on. After connecting to target orange light also turns on. ( connection happens)

But when i am connecting BDM programmer input voltage drops .(i/p voltage= 10 V, after connectingBDM programmer power supply getting into CC mode from CV mode, and power supply voltage drops to 2.5V), by default VCC (5V) also drops.( i think there must be some short circuit happening, but dont know where exactly). I tried all things on my controller board. But facing same thing.

What can be the problem???

Any solution?

Thanks & regards,

Sonal.

[RadekS]

Hi Sonal,

You placed this question also as new Community thread:

https://community.freescale.com/thread/375495

We could continue in discussion there.

Have a great day,
RadekS