Re: [avr-gcc-list] Bootloader question

[Eric Pasquier]

Scott,

You wrote:
<<I have narrowed down the code to about 10 lines in a timer overflow 
interrupt, when I comment it out it works fine.>>

Is it the same as  "if ((mod3 % 40) == -1)" ?


May be you should post a piece of code.

Eric.



----- Original Message ----- 
From: "Scott Morken" <address@hidden>
To: <address@hidden>
Sent: Friday, December 14, 2007 12:12 PM
Subject: Re: [avr-gcc-list] Bootloader question


> Hi
>
> I compiled my (apparently) troublesome interrupt code as follows It should 
> never run, this should hopefully eliminate any possibility of nested 
> interrupts?
>
>    if ((mod3 % 40) == -1)    //we are here 25x per second, for 25Hz 
> sampling rate filter code
>    {
>        .....
>     }
>
> But my problem still appears, and I cannot enter the bootloader from my 
> application, only if I reset the chip by toggling power.
>
> This makes me suspect my problem is related to program size, but the 
> numbers all look ok.
>
> The chip I am using is an ATmega168 and the bootloader section starts at 
> 0x3800.  With my troublesome code not commented out my program size is 
> 12674 (0x3182) and with it commented out (and working) the size is 12162 
> (0x2F82)
>
> Scott
>
> Eric Pasquier wrote:
> > Did you check that your treatment is not too long and that you do not 
> > have a problem with nested interrupt ?
> > How is your interrupt treatment ?
> > Is it possible to set the timer frequency differently to avoid the "mod3 
> > % 40" test ?
> >
> > Eric Pasquier
> >
> >
> > ----- Original Message ----- From: "Scott Morken" <address@hidden>
> > To: <address@hidden>
> > Sent: Friday, December 14, 2007 9:26 AM
> > Subject: [avr-gcc-list] Bootloader question
> >
> >
> > > Hi
> > >
> > > I have an application that jumps to the bootloader using this function 
> > > (it's a slightly modified avr109 bootloader made by atmel):
> > > void (*funcptr)( void ) = (void *)0x3800; // Set up function pointer to 
> > > the bootloader start.
> > >
> > > I call it when a command is sent over the serial port, making this code 
> > > run:
> > > UART_SendByte('B');
> > > wdt_disable();//disable watchdog
> > > cli();//disable all interrupts
> > > for(counter = 0; counter<20000; counter ++)
> > > {
> > >    asm("NOP");
> > > }
> > >                       funcptr();//goto bootloader
> > >
> > > It has been working great until some code was added to my application. 
> > > Now it will not enter the bootloader properly when I send the command. 
> > > I suspect the chip is crashing before it gets to the funcptr(); line.  I 
> > > have narrowed down the code to about 10 lines in a timer overflow 
> > > interrupt, when I comment it out it works fine.  Here are the suspect 
> > > lines. All of the arrays are floats and the capital letter variables are 
> > > integers:
> > >
> > >    if ((mod3 % 40) == 0)    //we are here 25x per second, for 25Hz 
> > > sampling rate filter code
> > >    {
> > >
> > >       //1st order, 7Hz -3dB lowpass, 25Hz sampling filter
> > >        xv4[0] = xv4[1];
> > >        xv4[1] = (float)GEN_V_DIV_ADC / 1.827271946;
> > >
> > >        yv4[0] = yv4[1];
> > >        yv4[1] = (xv4[0] + xv4[1]) + (-0.0945278312 * yv4[0]);
> > >
> > >        GEN_V_DIV_ADC_FILTERED = yv4[1];
> > >
> > >
> > >
> > >
> > >        //1st order, 3Hz -3dB lowpass, 25Hz sampling filter
> > >        xv5[0] = xv5[1];
> > >        xv5[1] = (float)SUPERCAP_DIV_ADC / 3.525711689;
> > >
> > >        yv5[0] = yv5[1];
> > >        yv5[1] = (xv5[0] + xv5[1]) + (0.4327386423 * yv5[0]);
> > >
> > >        SUPERCAP_DIV_ADC_FILTERED = yv5[1];
> > >
> > >
> > >    }
> > >
> > > Does anyone know of a reason why it would crash?
> > >
> > > Scott
> > >
> > >
> > >
> > >
> > >
> > >
> > > _______________________________________________
> > > AVR-GCC-list mailing list
> > > address@hidden
> > > http://lists.nongnu.org/mailman/listinfo/avr-gcc-list
> >
> >
> >
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>
>
>
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