Macronix MX25R6435F high performance mode - how to activate it?

[kobyfr]

The nRF52840 DK has a 64 mbit external flash on board. The MX25R6435F.

It's performance is too low, in terms of erase speeds - It takes several minutes to erase the entire flash.

We would like to speed that up.

We understand that this is the register to manipulate, for setting the external-flash in "high performance mode", doubling the erase speed.

We also know that the MX25R6435F registers can be accessed like so, as is apparent in the nordic SDK example projects:

    /* Get 3 byte identification value */

    uint8_t rdid_buf[3] = {0, 0, 0};

    cinstr_cfg.opcode = QSPI_STD_CMD_READ_ID;

    cinstr_cfg.length = NRF_QSPI_CINSTR_LEN_4B;

    ret = nrf_drv_qspi_cinstr_xfer(&cinstr_cfg, NULL, rdid_buf);

In what way should we update the configuration register, for achieving our goal of setting the external flash to high performance mode?

[kobyfr]

Thanks, but I already read it, and it is not what I asked for.

Let me rephrase:

Your SDK sample applications access the RDID register of the ext-flash, reading its content. That is done via nrf_drv_qspi_cinstr_xfer.
what I ask is this : Can all registers of the ext-flash be accessed using nrf_drv_qspi_cinstr_xfer? 

[awneil]

What does the memory datasheet say is the opcode required for that?

EDIT

nRF Available opcodes seem to be here:

which seem to correspond to Table 5 in the datasheet:

https://www.macronix.com/Lists/Datasheet/Attachments/7913/MX25R6435F,%20Wide%20Range,%2064Mb,%20v1.5.pdf

[kobyfr]

Thanks.

Specifically, this is the sequence to take to modify the configuration register(s):