Regarding the operation when LOW is put in the reset pin.

RE: Regarding the operation when LOW is put in the reset pin.

Kenneth — Tue, 18 Jul 2023 08:28:46 GMT

Hi,

I am not sure what you mean by breaking, but if you have a battery that is getting close to end of life, and you have some circuitry that draw a lot of current (e.g. motor), it could be that the application will startup and then start the motor (which cause the voltage to drop below operating conditions yes), this can cause a potentional starting up->BOR->starting up->BOR.. Not sure if it will break anything, but can be good idea to measure the battery voltage before starting the motor, and if the battery is low don't start the motor.

Kenneth

RE: Regarding the operation when LOW is put in the reset pin.

hirasaki — Tue, 18 Jul 2023 07:30:53 GMT

Thank you for your answer.

I have one last question.

Even if 1.7V and 1.5V are repeated in a short time, isn't there a risk of breaking?

image：Starting up ⇒BOR⇒Starting up ⇒BOR・・・

RE: Regarding the operation when LOW is put in the reset pin.

Kenneth — Mon, 17 Jul 2023 09:05:17 GMT

[quote user="hirasaki"]What will happen to the operation in the section ① until the BOR starts?[/quote]

The chip is fully functional until BOR trigger.

[quote user="hirasaki"]Is it correct to maintain the reset state for the section in ②?[/quote]

If BOR was triggered where you put the "start BOR" text, then BOR will be maintained until it reach operating conditions again (minimum 1.7V).

[quote user="hirasaki"]What kind of operation will occur in section ③?[/quote]

Nothing, the chip is in reset state.

[quote user="hirasaki"]I think the normal operation start voltage is 1.7V. What is the variation of 1.7V?[/quote]

All chips will be running when 1.7V, the chips will start running slightly below 1.7V.

[quote user="hirasaki"]Is system off mode the same? Just change 1.5V to 1.2V.[/quote]

Yes.

Kenneth

RE: Regarding the operation when LOW is put in the reset pin.

hirasaki — Thu, 13 Jul 2023 23:24:38 GMT

Sorry for the addition. please tell me the following

What will happen to the operation in the section ① until the BOR starts?

Is it correct to maintain the reset state for the section in ②?

What kind of operation will occur in section ③?

I think the normal operation start voltage is 1.7V. What is the variation of 1.7V?

Is system off mode the same? Just change 1.5V to 1.2V.

RE: Regarding the operation when LOW is put in the reset pin.

Kenneth — Thu, 13 Jul 2023 07:14:52 GMT

Hello,

Brown out reset (BOR) works independant of configuration of power failure warning (POF).

I would like to clarify one thing about BOR, the actual level BOR occurs depends on the mode the nRF52832 is using when VDD drop below 1.7V:

https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/power.html#unique_1095101570

If the chip is in system ON then BOR will trigger any place between 1.5-1.7V.

If the chip is in system OFF then BOR will trigger any place between 1.2-1.7V.

Kenneth

RE: Regarding the operation when LOW is put in the reset pin.

hirasaki — Thu, 13 Jul 2023 01:25:19 GMT

hirasaki said:

VDD：1.7V⇒1.5V⇒1.7V

If voltage supply drop below minimum operating conditions, then the brown out reset will trigger, and brown out reset will occur until supply voltage rise to minimum operating conditions again. After brown out reset the application will start from start of application code (like power on reset and pin reset etc).

Long time no see.
Additional question regarding the above.
It is said that the brown out reset trigger works, but does it work even if the part in the attached photo is set to Disabled?

RE: Regarding the operation when LOW is put in the reset pin.

Kenneth — Tue, 13 Jun 2023 08:27:08 GMT

[quote user="hirasaki"]・There is no possibility of breaking with the reset pin.[/quote]

There is no possibility to breaking the reset pin as long as the electrical pin level is within the electrical specification of the gpios specified in the datasheet of the nRF device.

[quote user="hirasaki"]・It doesn't matter if the reset pin falls from high to low while the MCU is powering up.[/quote]

This will not break the chip or break the pin no, however while the chip is in a reset state (powering up in this case), then we do not guarantee that pin reset will work. So you can't expect that pin reset occur in this case.

[quote user="hirasaki"]・While the microcomputer is starting up ⇒ reset pin is high to low ⇒ reset pin is low to high ⇒ while the microcomputer is starting up ⇒ reset pin is high to low ⇒ reset pin is low to high … Repeating this is no problem.[/quote]

Same answer as above.

Kenneth

RE: Regarding the operation when LOW is put in the reset pin.

hirasaki — Sun, 11 Jun 2023 23:21:24 GMT

I am very sorry to bother you when you are busy.
I wanted to know the possibility of the microcomputer being damaged by the reset pin.
Understood below.
・There is no possibility of breaking with the reset pin.
・It doesn't matter if the reset pin falls from high to low while the MCU is powering up.
・While the microcomputer is starting up ⇒ reset pin is high to low ⇒ reset pin is low to high ⇒ while the microcomputer is starting up ⇒ reset pin is high to low ⇒ reset pin is low to high … Repeating this is no problem.

RE: Regarding the operation when LOW is put in the reset pin.

Kenneth — Wed, 07 Jun 2023 12:14:26 GMT

I don't want to spend too much time on this.

Pin reset is intended to be used to reset the chip, you trigger pin reset by lowering it (=enter reset state: code stop executing immediately) and then set pin reset high (=start running code from startup). I am not aware of any situation this can fail.

Kenneth

RE: Regarding the operation when LOW is put in the reset pin.

hirasaki — Wed, 07 Jun 2023 12:05:30 GMT

I'm sorry again.
I have many quetions.

[quote userid="2111" url="~/f/nordic-q-a/100522/regarding-the-operation-when-low-is-put-in-the-reset-pin/429705"]

hirasaki said:
Kenneth said:
If resetpin high->low the chip immediately enter reset state: the CPU stop running code, the ports are undefined in reset state.

Even if a reset occurs during boot, won't it break?
Also, are there any expected problems?

If you apply vdd then chip then it will start by power up reset, if you pull reset pin low while or before vdd is ramping up, it might be slightly out of spec. It could immediately go to pin reset (waiting for pin reset to be released) or it might also start running the application (without waiting for pin reset to be released)

[/quote]

・It rises to at least 2.3V, is there any problem?
Reset pin goes low as soon as it rises above 2.3V.
・Regarding the possibility of starting execution of the application without waiting for the pin reset to be released What happens after running the application?
(I believe the reset pin stays LOW. Doesn't it take a reset?)

[quote userid="2111" url="~/f/nordic-q-a/100522/regarding-the-operation-when-low-is-put-in-the-reset-pin/429705"]

hirasaki said:
Kenneth said:
Undefined, it can be several hundreds of uA, even mA, so pin reset is not a low power mode. It's recommended to keep pin reset for short duration to reset the chip, not to use pin reset for long period of time.

Any reason why you shouldn't use pin reset for a long time?

It may deplete battery because it's not a low power operation, also the ports may be in an undefined state causing leds to be ON while pin reset is pressed.

[/quote]

Is it okay to say that there is no risk that the microcomputer will break?

[quote userid="2111" url="~/f/nordic-q-a/100522/regarding-the-operation-when-low-is-put-in-the-reset-pin/429705"]

hirasaki said:
VDD：1.7V⇒1.5V⇒1.7V

[/quote]

Is it okay to say that there is no risk that the microcomputer will break?

RE: Regarding the operation when LOW is put in the reset pin.

Kenneth — Wed, 07 Jun 2023 08:23:03 GMT

[quote user="hirasaki"]

Kenneth said:
If resetpin high->low the chip immediately enter reset state: the CPU stop running code, the ports are undefined in reset state.

Even if a reset occurs during boot, won't it break?
Also, are there any expected problems?

[/quote]

[quote user="hirasaki"]

Kenneth said:
If the chip is reset in the middle of a flash write, then the flash write may not complete, so it can be that the write is only

I'm sorry. I don't understand properly.
VDD is within the normal operating range, but does it mean that it is not reset after writing is completed?

[/quote]

The pin reset is a forceful hard reset, there is no logic in the chip that will ensure that any operation will complete no, the pin reset is immediate reset.

[quote user="hirasaki"]

Kenneth said:
Undefined, it can be several hundreds of uA, even mA, so pin reset is not a low power mode. It's recommended to keep pin reset for short duration to reset the chip, not to use pin reset for long period of time.

Any reason why you shouldn't use pin reset for a long time?

[/quote]

It may deplete battery because it's not a low power operation, also the ports may be in an undefined state causing leds to be ON while pin reset is pressed.

[quote user="hirasaki"]VDD：1.7V⇒1.5V⇒1.7V[/quote]

Best regards,
Kenneth

RE: Regarding the operation when LOW is put in the reset pin.

hirasaki — Tue, 06 Jun 2023 23:19:30 GMT

Thank you for your answer,
but I have many additional questions.

[quote userid="2111" url="~/f/nordic-q-a/100522/regarding-the-operation-when-low-is-put-in-the-reset-pin/429577"]If resetpin high->low the chip immediately enter reset state: the CPU stop running code, the ports are undefined in reset state.[/quote]

Even if a reset occurs during boot, won't it break?
Also, are there any expected problems?

[quote userid="2111" url="~/f/nordic-q-a/100522/regarding-the-operation-when-low-is-put-in-the-reset-pin/429577"]If the chip is reset in the middle of a flash write, then the flash write may not complete, so it can be that the write is only[/quote]

I'm sorry. I don't understand properly.
VDD is within the normal operating range, but does it mean that it is not reset after writing is completed?

[quote userid="2111" url="~/f/nordic-q-a/100522/regarding-the-operation-when-low-is-put-in-the-reset-pin/429577"]Undefined, it can be several hundreds of uA, even mA, so pin reset is not a low power mode. It's recommended to keep pin reset for short duration to reset the chip, not to use pin reset for long period of time.[/quote]

Any reason why you shouldn't use pin reset for a long time?
As in the additional question below, there is a risk of long-term pin resets.

●Additional question
Background
I'm thinking of using it for a handheld remote control.
Therefore, it is battery powered.
If the battery continues to be used, the voltage will drop.
If you press the remote control button in that state, the voltage will drop further.
When the battery voltage reaches around 1.7V, which is outside the guaranteed voltage range of the microcomputer, pressing the button will cause the following behavior.
VDD：1.7V⇒1.5V⇒1.7V
I think this is out of warranty.(I think that I have to start after setting it to 0.3V or lower, not 1.5V.)
As a countermeasure, we are trying to use a reset IC that works around 2.3V.

Is the above "VDD：1.7V⇒1.5V⇒1.7V" out of the operation guarantee?

RE: Regarding the operation when LOW is put in the reset pin.

Kenneth — Tue, 06 Jun 2023 13:36:35 GMT

Hello,

In all cases here I assume you have enabled pin reset in UICR and that you have perfomed a hard reset (=power on reset) to ensure that the pin reset is enabled.

https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/uicr.html#register.PSELRESET-0
https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/uicr.html#register.PSELRESET-1

[quote user=""]

condition1⇒VDD：2.4Ｖ、resetpin：LOW
condition2⇒VDD：2.4Ｖ、resetpin：HIGH

Whether the microcomputer startup process and port settings work when condition1 changes to condition2？

[/quote]

If resetpin low->high the behaviour is as described here:
https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/power.html#unique_961802881

[quote user=""]Is it okay to change from condition2 to condition1 during microcomputer startup processing and port setting?[/quote]

If resetpin high->low the chip immediately enter reset state: the CPU stop running code, the ports are undefined in reset state.

[quote user=""]Is there any problem even if it changes from condition2 to condition1 during writing process?[/quote]

If the chip is reset in the middle of a flash write, then the flash write may not complete, so it can be that the write is only partial.

[quote user=""]

condition1⇒VDD：2.4Ｖ、resetpin：LOW

What is the consumption current of the microcomputer at condition1？

[/quote]

Undefined, it can be several hundreds of uA, even mA, so pin reset is not a low power mode. It's recommended to keep pin reset for short duration to reset the chip, not to use pin reset for long period of time.

Kenneth