nRF51 S130 CPU blocking?

[Luis]

On this question I read that S110 is blocking CPU a lot during advertising/connection (devzone.nordicsemi.com/.../).

On this other question they say that you can change some parameter to make S110 in rev3 chips block much less during advertising (devzone.nordicsemi.com/.../).

On S130 specification 1.0.0 I read that by default it only blocks a little before or during each radio action (detailed on the specification), but most of the time CPU is free.

So which one is true for S130 and SDK9? Last one? Do I need to enable or change anything? Is it like this (almost free CPU) during scaning and both type of connections (slave and central)?

Update: forgot to say that I am using nRF51-DK, so nRF51 rev3 chipsets.

Thank you very much for your answer and time. :)

[Susheel Nuguru]

Hi LuisOnOff,

In S130, CPU is still blocked while preparing the radio and yes, this time is much less than the older versions but it is not almost free.

Being almost free depends on your advertising and connection interval. Looking at the S130 Radio notification says that the blocking is same as in S110 v7.0.0.

All the explanation of Ole Morten still holds and the main CPU block time has reduced from about 1ms to about 400us. Below is the logic output for S130V1.0.0,

connection interval of 500ms

Advertising interval of 40 secs on 3 channels

scan interval 100ms and scan window 50ms here you see that instead of 0.98ms in older versions it is now about 0.38ms.

[Luis]

Thank you for the answer. Then is there a way to unblock CPU more in S130 as described here devzone.nordicsemi.com/.../ ? I would find very useful if you could share a picture like above but for advertising on 3 channels and a scanning window on S130. Thank you

[Susheel Nuguru]

On S130V1.0.0 I think the CPU is not blocked for default. So you do not have to set opts explicitly. This means that the above picture already shows the unblocked version of minimum blocking from softdevice.

pictures added

[Luis]

Thanks a lot. Looks promising :)