UART interface during high flash memory activity

[A Knecht]

I'm having a problem that I get some presumable interference between a high flash memory activity and UART communication. I'm writing single words into flash quite often, leading to quite some time being spent in flash writes. I'm using fstorage with the SD backend and the SoftDevice is active, but only advertising.

I'm using nrf_serial with 128B FIFOs, 1B buffers, in IRQ mode with an event handler but no sleep handler attached. I'm reading from the serial library using the nrf_serial_read function with a timeout of a second. I never get a NRF_SERIAL_EVENT_DRV_ERR or NRF_SERIAL_EVENT_FIFO_ERR.

But still, there are quite frequent instances where single characters are read wrong from the serial interface.

If I comment out all the flash operations everything starts working fine.

What kind of interference could cause these problems?

The SDK is v15.3 and the SoftDevice S132 v6.1.1

[Jared]

Hi,

Are you using a custom board or the development kit? I'm surprised that you're receiving different characters then what you're sending as this shouldn't really happen. Could you provide a trace of the data that is sent on the UART line along with what is printed on the console?

regards

Jared