Significant Current Increase when programming flash 08QG8

[celsoken]

Hi,

I was working on a flash programming problem in QG8 BDM, SSDD. I realized that when flash programming was in course some Hiwave messages appear and the operation was aborted - Great news! I've been thru this at least 10 times before, specially in crytical phases - but the symptoms were quite different this time.

I've noticed a sudden current increase in current and due to shunt regulator topology, the current was over the "specs worst case" and the uP voltage dropped and caused the malfunction.

I can imagine that the flash charge pump could add some extra miliamps, but the boot of the charge pump really turned my regulator down.

I couldn't find on the specs any idea on this burst current, does anyone have a clue on what could be (worst case)?

Tks in advance,

Cheers,

Celso

Added p/n to subject.

Message Edited by NLFSJ on 2008-05-07 07:36 AM

[bigmac]

Hello Celso,

I wonder if the observed increase in current might be due to unterminated GPIO ports during the programming process.  Do you have many pins that are not externally pulled to a supply rail?  During normal operation, the ports would be initialised soon after reset, so would not get the current increase due to this potential cause.

How much extra current is required?  If using a shunt regulator, you might need to externally provide an additional constant current to the Vdd pin during programming.

Regards,

Mac

[celsoken]

Hi Mac,

You are right, I've got some unterminated inputs that certainly cause some noise when left floating, and in normal application they are programmed as outputs. They are not used because the product will work on a 8-pin device and the prototypes are based on 16-pin devices.

But I don't think it is the cause because (it rhymes) the problem starts on flash programming, there is a 100uF cap in power line and it dives +/-1V when flash programming take place. Anyway I'll place some pullups on unterminated pins to avoid this possibility.

Thanks Mac. Cheers,

Celso

[Zahar]

Celso,

What hardware interface and what software are you using to program the FLASH of your 9S08QG8 device.

If it is a P&E software/hardware please specify firmware and software version numbers.

Best Regards,
Zahar
P&E

[celsoken]

Dear Zahar,

I am using the embedded P&E multilink interface on DEMO9S08QG8 board. The software is inside CW 6.1 Release build 7285-29Oct07 w/ Service Pack PE V3.02, build 8.1.8.

Thanks in advance,

Celso