RE: Testing 48MHz QSPI and switching modes on QSPI chip requiring 2 clock rates in zephyr (nRF connect SDK)

Håkon Alseth — Thu, 07 Jan 2021 11:35:56 GMT

Hi,

The qspi module in zephyr sets the ifconfig1 once on init:

https://github.com/nrfconnect/sdk-zephyr/blob/master/drivers/flash/nrf_qspi_nor.c#L368

And there doesn't look like there's any API for dynamically changing this. You could run uninit (https://github.com/NordicSemiconductor/nrfx/blob/master/drivers/src/nrfx_qspi.c#L324) and init the module again with a new clock freq.

[quote user=""]and we might also need to add in some dummy clock cycle support - how do we go about doing this? It doesn't seem like Zephyr RTOS is designed around being able to cater for such a scenario.[/quote]

You can set the clock delay in IFCONFIG1 register: https://infocenter.nordicsemi.com/topic/ps_nrf5340/qspi.html?cp=3_0_0_6_24_10_49#register.IFCONFIG1

Have you looked at the QSPI hardware interface description and checked if this is sufficient towards the mode you're hoping to use? dummy data is being sent in some specific read modes:

https://infocenter.nordicsemi.com/topic/ps_nrf5340/qspi.html?cp=3_0_0_6_24_9#interface_description

Kind regards,

Håkon