S112, S113 support in nrf52833 and nrf52820 chipsets

[A.P]

Hi!

I'm slightly confused with the documentation regarding softdevices S112 and S113. Among other differences, its noted that SD S113 does not support nrf52820 chipset while SD S112 does.

When looking at the nrf52820 chip product page, this is noted: 'The nRF52833 DK is the recommended development kit, it emulates the nRF52820'. Surely, that means that the nrf52833 chipset is able to run the S112 SD.

1. Am I misunderstanding something?

2. If the nrf52833 can run the S112 SD, would it be correct to say nrf52820 should be able to run the S113 SD? I assume not.

Thanks!

[Susheel Nuguru]

Hi Asaf,

'The nRF52833 DK is the recommended development kit, it emulates the nRF52820'. Surely, that means that the nrf52833 chipset is able to run the S112 SD.

Since nRF52820 is the subset of nRF52833, you can run S112 and emulate nRF52820 on nRF52833 DK. But the vice versa is not true. That is you cannot emulate nRF52833 (S113) on a chipset with smaller features and peripherals. 

[Shahar]

Adding on the same question, seems weird that the nrf52820 can utilize the S140 (which is even more comprehensive in features than S113 or S112) according to this: https://www.nordicsemi.com/Products/Low-power-short-range-wireless/nRF52820/Download#infotabs

But the S113 is not supported?

[Susheel Nuguru]

I think it narrows down to the softdevice reserved peripherals on both variants being 100% compatible. When that is true, it is just the matter of testing and qualification. The below is not official doc, so please use it with a grain of salt.

In the above image you can see that the softdevice required/reserved peripherals on the three are compatible.Because of the limited RAM using S140 on nRF52820 only makes reasonable sense if you use the nRF52820 as a co processor for BLE.

[Shahar]

Thanks for the quick answer.

If I understand correctly, and based on the diagrams you attached, there's no limitation on having the S113 working on the nRF52820... or did I overlooked something?

Which makes the decision of having the S112 available for the nRF52833 and nRF52820 makes me wonder even more. 

As more work is required in enabling the S112 for nRF52820 (in addition to the nRF52833) as to simply enable the S113 which is already working on the nRF52833... (as S112 was designed primarily for the nRF52810 and nRF52832)

Who can we involve in having the a concrete answer on getting S113 enabled for nRF52820 or get definitive answer as to why not? as I don't see a hardware limitation.

[Susheel Nuguru]

You are right, there does not seem to be any hardware limitation to run S113 on nRF52820. 
The documentation is depending on what we tested and qualified. When we qualified S113, there was no nRf52820 available.

So short answer is, it should technically work to run S113 on nRF52820.

[Shahar]

The nRF52820 LE Data Packet Length Extension (DLE) is not utilized unless using S113 or S140.

Which is crucial for trying to achieve a higher utilization of the 2Mbps PHY.

Based on a response from Nordic RSM (was forwarded to me by my Local Rep), there's an upcoming release for S113 (August 2020?) which will enable +8db on nRF52840, nRF52833 and other +8db capable devices.

1. Could the S113 upcoming release include the official support for nRF52820?

This will result in enabling both +8db and DLE on the nRF52820 without too many changes to the SoftDevice code (if any) to accommodate for the inclusion of nRF52820 in S113.

2.  Regarding certification of the S113, you mentioned this:

Susheel Nuguru said:

When we qualified S113, there was no nRf52820 available.

But nRF52833 did exist, and it was certified to S113 but not S112 ... ? any reason for the discrepancy? 

Thanks

[Susheel Nuguru]

Shahar said:

1. Could the S113 upcoming release include the official support for nRF52820?

 Shahar, Can you please ask this to the RSM whom you can reach. I am not allowed to discuss roadmaps on this platform.

 

Shahar said:

But nRF52833 did exist, and it was certified to S113 but not S112 ... ? any reason for the discrepancy? 

Not sure why, but we can add this in the supported list when it is qualified.

[Shahar]

Susheel Nuguru said:

shaharhadas said:

But nRF52833 did exist, and it was certified to S113 but not S112 ... ? any reason for the discrepancy? 

Not sure why, but we can add this in the supported list very soon.

Just to be clear, my goal is to include nRF52820 in the S113 certified part list, (and not nRF52833 in S112)

Is this also something the RSM has jurisdiction over? or is this in under the someone else responsibility? 

[Susheel Nuguru]

Shahar said:

Is this also something the RSM has jurisdiction over? or is this in under the someone else responsibility? 

 No, RSM does not have juridiction over this, that combo needs to be qualified before you can have it in your certified part list.

[Susheel Nuguru]

Susheel Nuguru said:

Not sure why, but we can add this in the supported list when it is qualified.

 The person who is able to answer this question correctly told me that there is no plan to qualify S113 on nRF52820 as of now. If this is important to you, please escalate this to the RSM.