Ready interrupt in SPI RAW master (Serialization)

[yc38]

Hi,

I would like to use SPI raw master library (used on application chip in serialization examples) in my own application.

First, to understand well SPI raw implementation and verify signals I set up this configuration :

• 1 nrf51422 (nRF51-DK board) used as SPI raw master, flash with SPI serialization application chip example “ble_app_hrs_s110_spi_pca10028” (SDK10.0.0)

connected to

• my own microcontroller used as SPI raw slave

---

If I understand well SPI raw protocol, the /RDY signal controlled by slave could delay data transmission from master if it is disable during transfer (see figure1 in "SPI RAW protocol" chapter in SDKv10.0.0).

I wonder about this operation because when I try to disable /RDY line (low to high transition on my microcontroller) during master transmission, the master (nrf51422) react at this interrupt only after end of data transfer occured.

This figure shows an example :

The GPIOTE line represents progress (in/out) of the code in "GPIOTE_IRQHandler"

In this case the contribution of the /RDY signal is really poor! (because despite the /RDY signal is disabled master continuous transmission).

• Is it something that has already been notify by Nordic people or other developers?

• Why priority level interrupts seem to produce a different working as described in the SDK documentation (see chapter "SPI RAW protocol" in SDK documentation)?

Thanks

[yc38]

I agree with your remarks and effectively, SWI3 interrupt (use in SPI RAW driver) have higher priority level than GPIOTE. I already changed GPIOTE_CONFIG_IRQ_PRIORITY to HIGH.

But I would like to understand why using the default code provided by Nordic seems to cause a different operation from what is presented in SDK documentation?

I'm sorry about your questions but I can't give you much more info because it's confidential (professional project). I can just tell you that, for the purposes of application, nRF51 must manage the BLE and acts as the master while the 2nd microcontroller is seen as a peripheral (slave). Use SPI RAW master on nRF51 would be very convenient for exchanges coordination between the two microcontrollers.