SysTick Abweichung

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pvs-deck
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Re: SysTick Abweichung

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Posted: 28.03.2019 - 12:52  ·  #9
Quote by Merlin

You might want to take a look at my 'crude timers' with callbacks Crude timers. The code would need tweaking for your crystal, but the repetition would be very precise (not varying by much between successive callbacks). If you are using an oscillator accuracy would be poorer of course. Or maybe use OnSysTick?


Hello Merlin,
I take a look at your Crude Timers, thanks for the tip

Thorsten
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Re: SysTick Abweichung

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Posted: 28.03.2019 - 17:18  ·  #10
Hallo Thorsten,
geht das nicht evtl besser mit einem normalen Timerinterrupt. Die 62 Mhz lassen allerdings keinen genauen Teilerwert zu. Aber der Takt des ATXmegas wird je eh nicht sehr genau sein.


interrupt TCD0_INTOVF; // counterzeit 1 sec
begin
SekBol := true; //
end;

// in der main

// Timer setzen für ca. 1 sec Overflow @62MHz
TCD0PERL:= $83; // PERL - Period Register L Bite 7..0
TCD0PERH:= $EC; // PERH - Period Register H 15..8
TCD0CTRLA:= $07; // 3..0 Clock.select Prescaler 03= Clk/4 04: clk/8 05: clk/64 06: clk/256 07 : clk/1024
TCD0INTCTRLA:= $02;

// mit TCD0CTRLA := $00; ist der Timer Off

in der loop:

if SekBol= true then
SekBol:= false;
.......
endif;

Golf
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