8-bit MicrocontrollersのトピックProblem in my application board

Problem in my application board

santhu — Mon, 07 Jul 2008 17:10:43 GMT

In our project we use HCS08 family controller (MC9S08GB60).When we switch on the board the voltage across Vcc and Ground will maintain 3.3V and also RESET pin is always high,but the voltage between BKGD and Ground will start decreasing frm 3V to nearly 0.3V.So i not able to dump my code from PC (host) to target board.It shows the error saying that bus freequency changed from 4MHz to 0Hz and BKGD currently driven low.So there is no synchronisation between my target and host .There is no capacitor from BKGD pin of the controller to the BKGD pin in 6 pin connector which is used to connect BDM. I checked the voltage arross BKGD and GROUND after removing capacitor in EXTERNAL RESET path,then also i got the same result.Earlier this problem is not seen in the same board, recently this problem started and even in the new board also this problem there.

Can you suggest me what was the wrong in my board design,why the BKGD pin give low even BDM connected or disconnected to target.

Kindly suggest a solution for this problem

Re: Problem in my application board

DedsBee — Tue, 08 Jul 2008 02:16:46 GMT

Hi santhu,

I´m facing a similar problem. I developed a module using the MC13213 (that has an MC9S08GT60 integrated) and I found that the voltage in pin VDDA is 0.3V instead 1.8V. And the voltage in pin VDDVCO is decreasing from 1.8V to 0V. I think it´s solder issues, but if someone knows anything, please help us. If I find the solution, I will post here. And santhu, please tell me if you have some news.

Regards,

DedsBee

Re: Problem in my application board

Rodo55 — Tue, 08 Jul 2008 02:37:13 GMT

Hi Santhu,

I had similar trouble when I first started writing code on a DEMOQE board. I found that my code was causing the error. I wrote an illegal instruction and that caused a reset which caused the frequency to drop to zero.

A suggestion to determine if the board is an issue is to load one of the demo programs that came with the board and see if that runs OK. If it does I'd take a look at your code. If you are using CodeWarrior, look in the lower left corner of the Debugger in the "Command" window and see if there are any errors prior to the frequency going to zero. They might give you a direction to look in.

Good Luck,

Rodo

Re: Problem in my application board

santhu — Tue, 08 Jul 2008 11:30:54 GMT

hi DedsBee,

If i come to knw i will send the sollution for you.a the same time if u have sollution then send to me,all the best.

With regards

santhosh

Re: Problem in my application board

santhu — Tue, 08 Jul 2008 12:29:44 GMT

Hi Rodo,

Thanks for your suggestion.I checked command window in debugger before the frequency changed to 4MHz to 0Hz.The command window shows following errors saying that

1.Resetting the device for programming.

2.Error occred during flash programming.

After that i pressed Abort in the debugger.In that the debugger command window shows error saying that the debugger is currently not able to run due to loss of contact with hardware.(Between BDM and target board)

I think the reason behind my problem is BKGD becoming 0V.I attached my code.Plz check that and tell me if any wrong in that.In the code i'm taking sample of 3 phase AC.Suggest me if you come to knw what was the wrong in my hardware so that i will go ahead.

With regards

santhu

Re: Problem in my application board

santhu — Tue, 08 Jul 2008 12:29:50 GMT

Hi Rodo,

Thanks for your suggestion.I checked command window in debugger before the frequency changed to 4MHz to 0Hz.The command window shows following errors saying that

1.Resetting the device for programming.

2.Error occred during flash programming.

With regards

santhu

Re: Problem in my application board

santhu — Thu, 10 Jul 2008 20:33:01 GMT

hi DedsBee

My problem was solved.That is only because of soldering issue i think.Now my BKGD pin shows high with respect to GND.

I have one more problem for that i want sollution from your side.While debugging my code in the command window the frequency changed from 4MHz to 0Hz.After that one more diologue box (Power cycle diologue) saying that "Under 0.1V,turn MCU power ON and then click ok.This will attempt to enter debug mode through power on reset sequence (BKGD currently is driven low)".What this statement means.can u suggest me on this.

With Regards

Santhu