SPI External Flash Interface

[arjun]

Hi,

I am trying to interface external flash with the nrf52. I am able to read the device id. After writing to the status - configuration - bank address registers, I am able to read the register values.

But when I am trying to write to the flash and read from it, I am getting FF only. For reference, I went through the following documentation - infocenter.nordicsemi.com/index.jsp

For reading and writing, I have used the commands given in the above documentation (Write - 0x02 / Read - 0x0B).

Kindly give me some suggestions on, how to debug.

[vinayaka]

Hi Arjun,

        am also facing the same issue, can you please share the modification.

[arjun]

Hi Vinayak,

As per the issues I faced, I came to the following conclusions - 

First thing you have to do is configure the WP/HOLD pins as output. Set the both pins to high. This is to ensure that you have disabled the write protect on memory and you aren't holding the instructions by pausing your device (Hold - low).

Second thing is to always call write enable function (execute write enable command) before executing any fucntion that may cause change in the content of memory

Next thing is, after sending the write instruction(command+address+data) or any similar function, wait until Write in Progress (WIP) bit in the status register is set to zero. 

Regards