Timer use with FspTimer

Official Hardware UNO Family UNO R4 WiFi
1

Hello together, here I'm new but I have some experience with HC08 µC programming in C and Assembler.
I try to use an Arduino Uno R4 Wifi to capture an input signal with GPT321.
Unfortunately I didn't found an example for this and therefore I started to lern something about the timers and use the code from Phil Schatzmann without any changes. As far as I understand this code demonstrates a simple timer without any compare and capture settings.
I run the code and had a look at the cortex peripheral registers and now I'm a little bit confused.
Here are my questions:
1st. Why the FspTimer library sets with audio_timer.open() the register
GTCCRA, GTCCRB, GTCCRC and GTCCRD to 50% of the counter value in GTPR?

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2nd. Why I get three interrupt events in GTST? The TCFPO is clear but what is
with TCFA and TCFB?
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.

I would by happy for any help. Thank you in advance.

2

I don't chase random links.

If you read the pinned post re 'How to get the most from the forum' and follow that, you might get more help.

3

You can find various documents here:

Have you checked the hardware manual? It is the best document to understand the registers:
https://www.renesas.com/en/document/mah/renesas-ra4m1-group-users-manual-hardware

4

Audio is pulling and pushing air. When setting the "idle voltage" to 0V you cannot pull.

Setting it to 2.5V lets you do both. Now you only need a capacitor to remove the DC offset to prevent your speaker from burning...

See 22.2.16

  • TCFA: Input Capture/Compare Match Flag A
  • TCFB: Input Capture/Compare Match Flag B

BTW.: I did some capturing of the falling edge on a pin here.

5

Thank you for your response.

6

embeddedkiddie, thank you for your response. Yes, I know the manual. That is the reaseon that I'm confused. Regarding to the manual there is no necessity to set the register I mentioned and get the interrupts in saw-wave PWM mode.

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7

Rintin, thank you for your response and the explanations. "audio_timer" is just the name which Phil used. This is not the application. I assume the configuration for a simple counter in saw-wave PWM mode should follow Fig. 22.4 in 22.3.1.1. (s. above).

8

I haven't compared the FspTimer code for UNO R4 with the original Renesas code, so I can't say for sure, but since FspTimer is used in Tone(), it may have been customized for UNO R4?

9

Tone() may be off the mark, but FSP has a PWM function for audio, so that might be related.

For example... the following is an excerpt from the FSP manual:

AudioPlaybackPWM
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