MPSL ESB and BLE timer problem.

RE: MPSL ESB and BLE timer problem.

Håkon Alseth — Thu, 14 Aug 2025 12:19:29 GMT

Hi,

I am so sorry, I was supposed to edit out this comment:

[quote user="hkn"]I would recommend using the default timer for ESB, and then rather use another timer for the timeslot.[/quote]

This is not ideal either, due to the facts that you share.

My observation here is based on checking the current DPPI API vs GPPI API for the nRF54L-series device specifically:

[quote user="hkn"]GPPI does not handle groups, so you will hit another issue with using the nrfx_gppi implementation, unfortunately.[/quote]

There's a lack of certain APIs, mostly towards how groups are done. A workaround could be to loop over channels instead, but again; we're still in a discussion state, as we do not have proper support for this scenario.

I fully understand your considerations here:

[quote user="Eton"]Because not every MPSL function is accompanied by source code, we’re afraid that any misunderstanding on our part could lead to further headaches. Could you please spell out, step by step, how to replace the MPSL timer?[/quote]

The main problem is that we currently do not support esb + timeslot at this time, so the path-of-least-resistance does point towards your original thought, ie. add another timer instance to ESB, and setup DPPI/PPIB.

Kind regards,

Håkon

RE: MPSL ESB and BLE timer problem.

Alex — Thu, 14 Aug 2025 11:47:27 GMT

[quote userid="2115" url="~/f/nordic-q-a/123584/mpsl-esb-and-ble-timer-problem/545499"]GPPI does not handle groups, so you will hit another issue with using the nrfx_gppi implementation, unfortunately.[/quote]

nrfx_gppi will will hit another issue.Are there any other ways to do this? Could you operate it the same way as in my example function? I’m not familiar with this part, so I’m not sure if there are any issues.

[quote userid="2115" url="~/f/nordic-q-a/123584/mpsl-esb-and-ble-timer-problem/545472"]I would recommend using the default timer for ESB, and then rather use another timer for the timeslot.[/quote]

Because not every MPSL function is accompanied by source code, we’re afraid that any misunderstanding on our part could lead to further headaches. Could you please spell out, step by step, how to replace the MPSL timer?

RE: MPSL ESB and BLE timer problem.

Håkon Alseth — Wed, 13 Aug 2025 10:51:04 GMT

A correction towards my comment here:

[quote user="hkn"]That being said; you can use nrfx_gppi API instead, as this shall handle PPIB bridging for you.[/quote]

GPPI does not handle groups, so you will hit another issue with using the nrfx_gppi implementation, unfortunately.

Kind regards,

Håkon

RE: MPSL ESB and BLE timer problem.

Håkon Alseth — Wed, 13 Aug 2025 07:45:54 GMT

Hi,

[quote user="Eton"]If I want to solve this problem myself, could you please check if my understanding is correct?[/quote]

I would recommend using the default timer for ESB, and then rather use another timer for the timeslot.

Let's see what domains are set for the different bridges:

https://docs.nordicsemi.com/bundle/ps_nrf54L15/page/ppib.html#d1050e586

You want to connect the "RADIO PD" to "PERI PD", which is PPIB11.

Your logic looks correct.

That being said; you can use nrfx_gppi API instead, as this shall handle PPIB bridging for you.

[quote user="Eton"]Regarding this issue, what is the solution from the ESB team, and when is it planned to be resolved? Will it be addressed in a new release?
Is it possible to provide us with a version that solves the problem for early verification?[/quote]

I am sorry, but I do not have a timeline to communicate. The team has just recently started to look into what is required, so what I can tell you is that this is actively being developed.

If this is crucial for your product, please feel free to send me a direct message with your location and I will share the details of your local regional sales manager, so that we can get a more detailed response on the matter.

Kind regards,

Håkon

RE: MPSL ESB and BLE timer problem.

Alex — Tue, 12 Aug 2025 02:57:47 GMT

Thank you for your reply, it was like timely rain after a drought and answered my question precisely.

There are still a few aspects I would like to confirm:

If I want to solve this problem myself, could you please check if my understanding is correct?
For example,

void esb_ppi_for_wait_for_rx_set(void)
{
uint32_t channels_mask;

nrf_radio_publish_set(NRF_RADIO, ESB_RADIO_EVENT_END, radio_end_timer_start);
nrf_timer_subscribe_set(ESB_NRF_TIMER_INSTANCE, NRF_TIMER_TASK_START, radio_end_timer_start);

channels_mask = (BIT(radio_end_timer_start));

nrf_dppi_channels_enable(ESB_DPPIC, channels_mask);
}

changed to

void esb_ppi_for_wait_for_rx_set(void)
{
// RADIO PD
nrf_radio_publish_set(NRF_RADIO, NRF_RADIO_EVENT_END, radio_end_timer_start);
nrf_ppib_subscribe_set(NRF_PPIB11, nrf_ppib_send_task_get(0), BRIDGE_CHANNEL);
nrf_dppi_channels_enable(ESB_DPPIC, channels_mask);

// PERI PD
nrf_timer_subscribe_set(NRF_TIMER20, NRF_TIMER_TASK_START, 0);
nrf_ppib_publish_set(NRF_PPIB21, nrf_ppib_receive_event_get(0), BRIDGE_CHANNEL);
nrf_dppi_channels_enable(ESB_DPPIC, 0);
}

Regarding this issue, what is the solution from the ESB team, and when is it planned to be resolved? Will it be addressed in a new release?
Is it possible to provide us with a version that solves the problem for early verification?

RE: MPSL ESB and BLE timer problem.

Håkon Alseth — Mon, 11 Aug 2025 08:05:00 GMT

Hi,

For the nRF54L-series target, only TIMER10 is supported at the moment.

As you have noticed, this conflicts with the MPSL timeslot timer, thus MPSL timeslot + ESB is not yet running as expected for the nRF54L-series devices.

Since the radio power domain only has one timer instance:

https://docs.nordicsemi.com/bundle/ps_nrf54L15/page/overview.html#ariaid-title2

other timer options must be used from other power domains, which will require "PPIB", ie. bridging between the domains, in order to run properly:

https://docs.nordicsemi.com/bundle/ps_nrf54L15/page/ppi.html

This is a feature request that has been raised to the ESB team.

Kind regards,

Håkon