GPIO and clock on F28069

Constantine Musatoff

It is my first C2000 project.

I have Docking-Stn + F28069 card.

I load project Example_2806xGpioSetup. I add to the end of main

while( 1 )
{
GpioDataRegs.GPATOGGLE.bit.GPIO6 = 1;
GpioDataRegs.GPATOGGLE.bit.GPIO7 = 1;
GpioDataRegs.GPATOGGLE.bit.GPIO8 = 1;
GpioDataRegs.GPATOGGLE.bit.GPIO9 = 1;
}

and obtained meander on GPIO6 that is good.

I change in function InitSysCtrl call from IntOsc1Sel to XtalOscSel and program work.

Parameters of PLL (InitPll(DSP28_PLLCR,DSP28_DIVSEL);) is 9 and 2 and xtall on board is 20 MHz. System clock 20 * 9 / 2 = 90 MHz.

On oscillocsope I see time between switches about 480 ns. In debugger I see that circle of my code is 6 asembler commands. Thus time of execution of one command is 80 ns. Is it correct or where I mistake?

over 13 years ago

0 Brett Larimore over 13 years ago

TI__Guru 57255 points

Constantine,

Good to hear that things are moving along.

Your question here and more is answered in the C2000 wiki:
http://processors.wiki.ti.com/index.php/General_Purpose_IO_%28GPIO%29_FAQ_for_C2000

Basically each ".bit write" instruction will force a full pipeline clear. This adds cycles but gives convenience. There are other methods of toggling GPIOs which are faster.

Thank you,
Brett

0 Constantine Musatoff over 13 years ago in reply to Brett Larimore

Intellectual 880 points

Thank you, Brett!

0 Constantine Musatoff over 13 years ago in reply to Constantine Musatoff

Intellectual 880 points

One more question.

I create new project In CCS 5 for this microcontroller and get all source codes from demo project:

main.c
F2806x_SysCtrl.c
F2806x_usDelay.asm
F2806x_SWPrioritizedDefaultIsr.c
F2806x_PieVect.c
F2806x_PieCtrl.c
F2806x_Gpio.c
F2806x_GlobalVariableDefs.c

and headers.

I check that build, compiler, linker and debug options are the same

All works except that GPIO not changes states. Commands executes but values of GPIO data registers do not changes and voltage on pins not changes.

What I did wrong?

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GPIO and clock on F28069