LPC MicrocontrollersのトピックRe: LPC8N04: Application needs a reset to start after programming

LPC8N04: Application needs a reset to start after programming

DDTD — Tue, 17 May 2022 00:07:48 GMT

Hello everyone:

We are developing an application for LPC8N04 and we have the next problem.

Once the LPC8N04 is programmed through the debugger and the PCB is running standalone, the application runs only until a reset signal is placed in the Reset pin, this behavior is replicated every time the MCU is powered.

I have been researching about some problems in the bootloader but at the time it seems to be fixed due to the auto generation and programming of the checksum in the right memory slot.

I just saw that the LPC8N4 default application needs to receive the same reset signal once the MCU is powered up.

Is this the expected behavior for every application loaded?

Is there a way to avoid the need of a reset signal once the MCU is powered?

Regards

Re: LPC8N04: Application needs a reset to start after programming

frank_m — Tue, 17 May 2022 06:25:20 GMT

> I just saw that the LPC8N4 default application needs to receive the same reset signal once the MCU is powered up.

Normally, you only do this to get the MCU into a specific mode, i.e. pull the mode pins to certain levels to get it into ISR mode (ROM bootloader).

If the board does not run after power-up, you might have a power supply issue. Which means, the power supply is not yet stable when the L-H transition at the reset pin occurs.

The most common method to correct this is to prolong the reset signal at power-up, in the simplest case with a RC element.

Re: LPC8N04: Application needs a reset to start after programming

DDTD — Tue, 17 May 2022 22:02:14 GMT

Hi @frank_m,
The RC solved the issue.

Thanks!