Constant Latency vs Low Power mode

[Frikkie Badenhorst]

Hi there,

We are currently doing some testing around the low power modes of the nrf5340. Detailed info on the Low Power mode and Constant Latency mode is a bit hard to find.

According to the manual, low power mode comes at the prices of latency. Is it possible to point me to information on what this latency is? Also, what will latency be during Constant Latency?

Looking forward to a response!

Regards,

Frikkie

[radek tanski]

Yes, to add to the question, what is the worst case low power interrupt latency assuming all systems are in low power. additionally what considerations should be taken to minimize interrupt latency when in low power mode?

We would be using the network core with 10ms slots that have very critical timings internally for receiving and transmitting. will the low power mode be able to handle that situation? 

[Elfving]

Hello Frikkie and Rodek,

I will have to get back to you on this.

Regards,

Elfving

[Elfving]

Hello again Frikkie and Rodek, sorry about the delay.

Detailed info on the Low Power mode and Constant Latency mode is a bit hard to find.

Yes it unfortunately can be. There is some available in the Product Specification. There you can see that the constant latency mode will give you a "Time from IDLE to CPU execute" delay of 10µs.

Low power mode comes with variations in CPU wakeup latency and PPI task response. It is hard to give any official numbers for this because it depends on what the state of other internal "voltage nets" are when you're entering sleep. it takes time to start up HFRC, flash, etc.

Regards,

Elfving