About SoftDevice interrupt occupancy time

RE: About SoftDevice interrupt occupancy time

Vidar Berg — Tue, 02 Apr 2024 06:47:28 GMT

Hello,

[quote user="hiroiwas"]Priority 0 is written as SoftDevice timing critical, I assume this refers to the timeslot API using the timer 0 peripheral and the transmit/receive interrupts from the wireless peripheral.[/quote]

The timeslot itself is not running in an interrupt context (Multiprotocol support), but TIMER0 and RADIO are assigned the highest interrupt priority ('0').

[quote user="hiroiwas"]Priority 1 is written as SoftDevice memory protection, so I understand that this is a fail-safe purpose that will not occur as long as the memory used by SD and APP are separated.[/quote]

Yes, the memory protection mechansim will invoke the app error handler if the app attempts to access memory (RAM or peripheral) reserved to the Softdevice. System on Chip resource requirements

[quote user="hiroiwas"]Priority 4 is for API calls and non-time-critical processing, but do all SD APIs go through this interrupt?
Also, what exactly does non-time-critical processing mean?
I believe that this is a callback event from SD via an observer.[/quote]

Yes, all SD APIs are implented as SVCs (Application programming interface)

[quote user="hiroiwas"]I believe that this is a callback event from SD via an observer.[/quote]

The Softdevice events are reported to the application via the SD_EVT_IRQn, which is an application interrupt with priority 6.

Best regards,

Vidar

RE: About SoftDevice interrupt occupancy time

hiroiwas — Thu, 28 Mar 2024 07:50:40 GMT

Hello, Vidar.

Listed below, Is my recognize correct?

Priority 0 is written as SoftDevice timing critical, I assume this refers to the timeslot API using the timer 0 peripheral and the transmit/receive interrupts from the wireless peripheral.
Priority 1 is written as SoftDevice memory protection, so I understand that this is a fail-safe purpose that will not occur as long as the memory used by SD and APP are separated.
Priority 4 is for API calls and non-time-critical processing, but do all SD APIs go through this interrupt?
Also, what exactly does non-time-critical processing mean?
I believe that this is a callback event from SD via an observer.

Best regards.

RE: About SoftDevice interrupt occupancy time

Vidar Berg — Mon, 25 Mar 2024 11:20:44 GMT

Hello,

The interrupt processing times for various Bluetooth events are documented in the Bluetooth Low Energy processor usage patterns section of the Softdevice specification.

Best regards,

Vidar