BDM compatibility - DEMO9S08QG8

[jorgen]

Dear everyone,

I have a DEMO9S08QG8 board from Freescale. This board has an integrated BDM based on the MC9S12UF32. Can I use that BDM for other S08 MCUs on other boards like a board designed by myself? Do I have to make changes other than removing the S08QG8 from the DEMO9S08QG8 board and soldering on a 6 pin header box?

Regards,

jorgen

Added p/n to subject.

Message Edited by NLFSJ on 2008-01-07 10:38 AM

[bigmac]

Hello jorgen,

It should be possible to use the DEMO9S08QG8 board in the manner you require, with the changes that you suggest.

Regards,

Mac

[jorgen]

Dear Mac,

Thank you for your reply. I am still puzzled about voltage levels. Some S08 devices are 5V while others are 3.3V so a BDM must need some setting to work with different voltages, unless of course one lets the target system be powered by the BDM, which has quite some limitations on the peripherals of the target system.

Regards,

Jorgen

[bigmac]

Hello Jorgen,

Running the target MCU from a 3.3 volt supply, derived from pin 6 of the BDM header, may be a problem for 5 volt external peripherals during a debug session.  However, since it appears that all 5 volt HCS08 devices are capable of operation at 3.3 volts, this should not present a problem for in-circuit programming.

On the schematic for the demo board, I notice that the circuit block representing the USB to BDM interface shows a Vcc_IN connection, to which Vdd is applied, from whichever source is used.  I assume this is to allow for some variation of Vdd.  The question still remains whether the voltage variation may extend to 5 volts.

To test this capability, the target Vdd should be applied to BDM header pin 6, and PWR_SEL jumper completely removed, as Peg has indicated.  The Vx_EN jumper shouldn't matter since the connector J1 will not be used in this instance.

Regards,

Mac

[jazz]

Just wanted to do the same: use the DEMO9S08QG8 board as a BDM to external board in-circuit programming, and this thread helped me a lot.

Target Vdd was 3V.

In just 30 minutes and a little soldering I've had it working. Make sure the PWR_SEL jumper is removed from the DEMO board.

Nice and simple.

Thanks Bigmac!

Jazz

[JimDon]

If you don't need to to power the board, it will work on HCS12 as well.
I've tried it.

[peg]

Hi Jorgen,

Yes you can certainly use your DEMOQG8 as a BDM adapter for external 3.3V devices.

The P&E USB Multilink on which it is based does not supply power to the target. You have to supply it with power (usually from the target) to make it work. It will work with target voltages from 1.8 to 5V.

What I am unsure of is whether they bothered to include the level translators within the BDM bit when they are not really required for the on board device. If they are there then you could leave of the PWR-SEL and VX jumpers and power your target from 5V  or whatever.

You may need to investigate this for yourself as I don't have one of these boards.
There is nothing else required for different voltages, only level translation.

[celsoken]

Dear Jorgen,

Yes, I did that and it is a fast BDM probe. Faster than the spyder and OSBDM, maybe because it is an USB 2.0 BDM. I just tested with the QG8, I'm not sure it will work with other processors.

In my case I used to program Qg8s in a production test equipment.

Cheers,

Celso

[jorgen]

Dear Celso,

Thank you for replying. I am still puzzled about voltage levels. Some S08 devices are 5V while others are 3.3, so some setting must be required on a BDM to work with both. I have noticed that the SPYDER works with the 3.3V devices only although the S12 inside the SPYDER is a 5V device, but the SPYDER includes 5V / 3.3V logic converters build in a clever way using a BSS138 MOSFET in both drain->source and source->drain mode.

The other issue is the "power on reset" story also reported in another thread.

Well there is probably only the hard way left, read the documentation and try.

Regards,

jorgen

[celsoken]

Dear Joergen,

I think Peg is right in general terms, but I had some troubles with the QG8demo boards so I knew by the hard way that some restrictions apply.

There is an SN74LVC2G66 analog switch that is powered by the EVM board with 3.3V. This sets at least a clamping level for BKGND and /RST lines. The 9S12 is protected by series-connected 47R resistors, but the switch can be burned. Thanks god Digikey has got them in stock.

If you wanna work with 5V devices, I suggest you try to use some level converters.

Good luck,

Celso