nrf8001 Reset - RDYN and REQN behavior

[brian]

Hi,

I'm developing some code for an AVR MCU with the Adafruit nrf8001 and had a question about the expected behavior of the handshaking lines, REQN and RDYN

My understanding is, once the device comes out of Reset (Reset Low -> High) the RDYN line should output to logic low indicating that the DeviceStartedEvent is ready to be clocked out over SPI like so.

To clock the event out, the user application should then toggle the REQN line low and begin clocking data out over SPI. However, when the REQN line transitions (from either High to Low or vice versa) I see a small pulse on the RDYN line (like so)

Any ideas what this could be and if this is ok? So far my application only goes in an infinite loop of Reseting the device, and driving the REQN low once RDYN also goes low, waits ~100ms then resets the nrf8001 again

EDIT: Added new picture of "glitch" after device reset

[brian]

Haven't moved the design to a PCB yet, but am using the Adafruit nrf8001 breakout with a bare AVR on breadboard.

Markings on IC show NRF D/8001/ 1338 JP

I've added a new, zoomed in, logic analyzer trace to the original post, showing the "RDYN" glitch after toggling the RESET pin low. It looks like the RDYN pin follows the MISO pin (not previously shown), and proceeds the REQN line transition.

Of note, after the device is reset, I am able to successfully read the DeviceStartedEvent so I think the ACI connections are correct.