QSPI vs SPI for external memory

RE: QSPI vs SPI for external memory

CheMax — Fri, 07 Jun 2019 10:20:33 GMT

What moments should I pay attention to when installing here such a memory MX25U51245G . Interface SPI (x1 /x2 /x4 lines). Capacity 512 Mb.

I apologize if the question is not at the address.

RE: QSPI vs SPI for external memory

Andy — Fri, 07 Jun 2019 09:29:56 GMT

Can help with what?

RE: QSPI vs SPI for external memory

CheMax — Fri, 07 Jun 2019 09:04:36 GMT

Ok, thanks.
we just decided to add an external drive to our device. picked up the memory of the same type that is installed on the nrf52840 DK, but a larger volume (512 Mb). But since they have not worked with her before, there are some uncertainty. So we decided to collect some information.
Maybe you can help?

RE: QSPI vs SPI for external memory

Andy — Fri, 07 Jun 2019 08:51:21 GMT

We are using some modules from Cypress Semiconductor. I developed the driver myself, but it's not a big deal to implement it if you read the datasheet carefully.

RE: QSPI vs SPI for external memory

CheMax — Fri, 07 Jun 2019 08:31:47 GMT

Hello, Andy.

Can you tell (if this is not a commercial secret) what type of memory did you use? The driver for the work developed independently or taken ready?

Thank you in advance.

RE: QSPI vs SPI for external memory

Andy — Tue, 21 May 2019 15:40:00 GMT

If you can afford the GPIOs and the peripheral blocks, why not?

RE: QSPI vs SPI for external memory

RO — Tue, 21 May 2019 15:33:47 GMT

I guess read speed isn't of paramount importance in my application. I will have to transfer data from the external flash to the SD card though. So in this case its fine to have 2 SPI interfaces, each to SD card and external flash?
Thanks

RE: QSPI vs SPI for external memory

Andy — Tue, 21 May 2019 15:23:22 GMT

I guess it depends on your application.

In my application I work with 2 GB of external flash to store data while a connection isn't active. When the connection is reestablished, the data is read out from flash and sent to the client.

Since I can read data over SPI much faster than I can send it over BLE, I just used SPI. I don't really see a need to speed up the data transfer between the external flash and the NRF52, therefore no need to use QSPI. You also save some GPIOs.

However, I can imagine applications where reading (or writing) data from/to flash as fast as possible is paramount. In this case I would use QSPI.