I am unable to activate the 4-wire QSPI of NRF52840

RE: I am unable to activate the 4-wire QSPI of NRF52840

Vidar Berg — Tue, 21 Oct 2025 10:22:11 GMT

The ifconfig registers must be configured prior to enabling if you follow the steps outlined in the PS here: https://docs.nordicsemi.com/bundle/ps_nrf52840/page/qspi.html#ariaid-title2, and this is already done by the driver init function. Have you verified that the init function is setting up the interface as you want it?

RE: I am unable to activate the 4-wire QSPI of NRF52840

Gin — Sat, 18 Oct 2025 04:55:09 GMT

My LCD driver chip supports a single/double/four wire QSPI interface, and many operation commands are the same as those of QSPI FLASH devices. I can use the QSPI custom interface of NRF52840 to drive the display screen successfully, but the speed is too slow, because the custom mode uses a single wire transmission. But in the above code, after I configure the four wire mode, I call nrfx_qspi_write() to send, and the QSPI is always busy, as if it has been sending without stopping. Calling write again will return the QSPI busy state. I don't know what this is, and what interface can manually stop this state?

Thank you very much for your help

RE: I am unable to activate the 4-wire QSPI of NRF52840

Vidar Berg — Fri, 17 Oct 2025 10:00:00 GMT

Hello,

I'm not able to see from the code why it's not switching to quad mode. However, please note the the QSPI peripheral on the nRF52840 is designed to work with external flash ICs as discussed in this post: Driving high-resolution displays over QSPI . Is it an alternative to use the HS SPI instance instead?

Best regards,

Vidar

RE: I am unable to activate the 4-wire QSPI of NRF52840

Gin — Fri, 17 Oct 2025 07:58:56 GMT

When I started the write function to send, I used an oscilloscope to see that the CLK and IO0 pins were constantly generating signals, and IO1-IO3 were not outputting. It looked like QSPI was busy and had not exited