Maybe a stupid question, about TCA timer in split mode (attiny 814)

[yuranikspb]

I watched example

  pinMode(PIN_PB0, OUTPUT); //PB0 - TCA0 WO0, pin7 on 14-pin parts
  pinMode(PIN_PA5, OUTPUT); //PA5 - TCA0 WO5, pin1 on 14-pin parts
  TCA0.SPLIT.CTRLB=TCA_SPLIT_LCMP0EN_bm|TCA_SPLIT_HCMP2EN_bm; //PWM on WO5, WO0
  TCA0.SPLIT.LPER=0xFF; // Count all the way down from 255 on WO0/WO1/WO2
  TCA0.SPLIT.HPER=200;  // Count down from only 200 on WO3/WO4/WO5
  TCA0.SPLIT.LCMP0=0x7F; //50% duty cycle
  TCA0.SPLIT.HCMP2=150;  //75% duty cycle
  TCA0.SPLIT.CTRLA=TCA_SPLIT_CLKSEL_DIV1_gc|TCA_SPLIT_ENABLE_bm; //enable the timer with prescaler of 1

and i watched data sheet ? but don't understand:
TCA0.SPLIT.HCMP2 channel to PA5 pin or (wo5)
TCA0.SPLIT.LCMP0 channel to PB0 pin or (wo0)

TCA0.SPLIT.HCMP1 channel to what pin ?
TCA0.SPLIT.HCMP0 channel to what pin ?
TCA0.SPLIT.LCMP2 channel to what pin ?
TCA0.SPLIT.LCMP1 channel to what pin ?

?

[SpenceKonde]

Lcmp0-2 go to wo0-2, on pins pb0-2 Hcmp0-2 go to wo3-5, on pins pa3-5.(mapping o 8-pin parts is different) There is also an alternate pin for each of the pins that can be selected with one of the portmux registers (6 bits, one per pin, so they can be chosen individually unlike larger parts where all the TCA channels move as a group) though the core only configures it in the case of the 8 pin parts, iirc.

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On Wed, Apr 7, 2021, 08:06 yuranikspb ***@***.***> wrote: I watched example pinMode(PIN_PB0, OUTPUT); //PB0 - TCA0 WO0, pin7 on 14-pin parts pinMode(PIN_PA5, OUTPUT); //PA5 - TCA0 WO5, pin1 on 14-pin parts TCA0.SPLIT.CTRLB=TCA_SPLIT_LCMP0EN_bm|TCA_SPLIT_HCMP2EN_bm; //PWM on WO5, WO0 TCA0.SPLIT.LPER=0xFF; // Count all the way down from 255 on WO0/WO1/WO2 TCA0.SPLIT.HPER=200; // Count down from only 200 on WO3/WO4/WO5 TCA0.SPLIT.LCMP0=0x7F; //50% duty cycle TCA0.SPLIT.HCMP2=150; //75% duty cycle TCA0.SPLIT.CTRLA=TCA_SPLIT_CLKSEL_DIV1_gc|TCA_SPLIT_ENABLE_bm; //enable the timer with prescaler of 1 and i watched data sheet ? but don't understand: TCA0.SPLIT.HCMP2 channel to PA5 pin or (wo5) TCA0.SPLIT.LCMP0 channel to PB0 pin or (wo0) TCA0.SPLIT.HCMP1 channel to what pin ? TCA0.SPLIT.HCMP0 channel to what pin ? TCA0.SPLIT.LCMP2 channel to what pin ? TCA0.SPLIT.LCMP1 channel to what pin ? ? — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#382>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABTXEW2UQ5PG7RMKJSMC7YDTHRDCVANCNFSM42QVBBLQ> .

[yuranikspb]

"Lcmp0-2 go to wo0-2, on pins pb0-2 Hcmp0-2 go to wo3-5, on pins
pa3-5"
Thx.
But where this informationin datasheet.?

pinMode(PIN_PA3, OUTPUT); //PA3- TCA0 WO3, 
 TCA0.SPLIT.CTRLB=TCA_SPLIT_LCMP0EN_bm|TCA_SPLIT_HCMP2EN_bm; //PWM on WO5, WO0
 TCA0.SPLIT.LPER=0xFF; // Count all the way down from 255 on WO0/WO1/WO2
 TCA0.SPLIT.HPER=50;  // Count down from only 50 on WO3/WO4/WO5
 
 TCA0.SPLIT.HCMP0=25;  //50% duty cycle
 TCA0.SPLIT.CTRLA=TCA_SPLIT_CLKSEL_DIV1_gc|TCA_SPLIT_ENABLE_bm; //enable the timer with prescaler of 1

does this example give me 400 khz on pa3 ? with duty cycle 50%? cpu 20mhz

[yuranikspb]

I test my last example.Iit doesnt work! why ?

[SpenceKonde]

That example looks correct to me, except that you don't enable the output on WO3:
TCA0.SPLIT.CTRLB=TCA_SPLIT_LCMP0EN_bm|TCA_SPLIT_HCMP2EN_bm; //PWM on WO5, WO0

you want
TCA0.SPLIT.CTRLB=TCA_SPLIT_HCMP0EN_bm;

Quick look at the 214/414/814 datasheet (DS40001912C, I think is the latest version), I see it on pg 185, Figure 20-13. Timer/Counter Block Diagram Split Mode. It's probably stated elsewhere too Atmel datasheets were never great about putting the information on what signal goes to which pin in the part of the datasheet that you are looking when you need it but I think they've gotten worse on that front since the 2016 apocalypse. On the other hand, everything else about the parts and docs has improved, so I'm not complaining. Obviously the most useful 1-2 pages of the datasheets now are always going to be "I/O Multiplexing and Considerations" table from a datasheet covering the largest-pincount part in a family - but it sounds like your question was "how do we know which register in split mode corresponds to which WO pin?" And I think that's just figure 13 from the TCA chapter. Some of the newer parts say it in Register Descrioption, Split Mode for the CTRLB register. 814 datasheet is missing that sentence thoug.

[yuranikspb]

To change duty cycle on fly
a must change TCA0.SPLIT.HCMP0 only ?
or i need stop timer and start.

[SpenceKonde]

No need to stop and start the timer, just write the register. with TCA I think the only things you need to stop timer for are "hard reset" command, and... maybe turning split mode on or off? I think everything else you can leave it enabled for.

TCD0 is the one you need to stop and restart to change almost anything on, TCA0 isn't weird like that.. Duty Cycle is about the only thing on TCD0 that you can change without stopping the timer.

[yuranikspb]

Thx!
Please, dont close this issue some days , may bei will keep ask any question in this topic about TCA

[SpenceKonde]

In that case... I converted it to a "discussion" :-)