RE: About custom instruction of QSPI and dummy byte

Simonr — Mon, 19 Sep 2022 13:07:15 GMT

Hi Youngjun

I'm afraid we don't support setting up NAND flash devices with our QSPI, as the configuration and setup is exponentially more complicated than with NOR flash devices, so I'm afraid you're mostly on your own here. We strongly recommend using a NOR flash, as the only use case I've seen a NAND flash work, in practice took away the "quad" feature in QSPI, as you'll likely be left with the speeds available in normal SPI.

Here's what I know about your questions:

1. I think though, that you can configure the number of dummy cycles on the memory side in the flash device's Nonvolatile Configuration Register. I think you can try increasing this to get a dummy cycle after a command.

2. The NRF_QSPI_CINSTR_LEN parameter is the length of your custom instruction, where one of the bytes is the OP code, and the rest are custom instruction data.

Best regards,

Simon