nrf51822: Interfacing external flash memory using SPI

[sidekick]

We have a custom board on which we have NRF51822 SOC. We also have a small external flash memory(From Spansion) on our board. I'm trying to figure out the ways to use this external non-volatile flash memory as SPI slave. NRF51822 would act as master and will store some information on this non-volatile flash memory. I've read the documentation on SPI from the nRF51_Series_Reference_manual v3.0 (section 26) and also read the API documentation on SPI master driver. So far so good, but It would be of tremendous help If someone can point me to simple slave implementation(Preferrable a flash memory block).

Also, Are there any slave related APIs as well(something similar to spi_master_open) and if yes then how to use such API in my scenario ?

Thanks a lot.

[Clem Taylor]

For the typical SPI flash the nrf51 is the master and the spi flash is the slave.

The nrf51 SPI slave is mostly intended for BLE serialization, where you are using the nrf51 with an external processor (which acts as the SPI master).

I'm not using the SDK SPI driver, but I am using NRF_SPI0 (spi master) to talk to both a GigaDevice GD25LQ16 2MB and a SSD1306 based OLED display. I wish the nrf51 SPI interface was lower overhead (DMA or tx/rx FIFO would be nice). The software overhead means I can't quite keep up with a 4mbit interface. For flash writes I spend more time transferring the data then doing the actual write.

[sidekick]

I've been able to successfully write to this external NVRAM memory block as SPI slave. Hence closing this thread.

[sidekick]

Thank you for your inputs. For our application, the speed is not of much importance, hence the normal SPI master-slave configuration works for us.

[Susheel Nuguru]

I really appreciate you coming back and posting your progress. This practice makes this devzone more efficient. Thank you sidekick