Connection examples

This section contains examples on how two connect two PPI systems using PPIB.

The following example shows how to create a PPIB connection between the TIMER10 compare event in the RADIO PD and the SAADC start task in PERI PD. PPIB11 in RADIO PD is hardwired to PPIB21 in PERI PD, which allows the PPI systems in the two separate power domains to connect. DPPI channel 0 is used by both power domains. Note that it is only necessary to use the same DPPI channel within the power domain; different DPPI channels can be used across power domains. An example of this is given further down in this section.

    // RADIO PD
    NRF_TIMER10->PUBLISH_COMPARE[0] = (0<<TIMER_PUBLISH_COMPARE_CHIDX_Pos) | TIMER_PUBLISH_COMPARE_EN_Msk;
    NRF_PPIB11->SUBSCRIBE_SEND[0] = (0<<PPIB_SUBSCRIBE_SEND_CHIDX_Pos) | PPIB_SUBSCRIBE_SEND_EN_Msk;
    NRF_DPPIC10->CHENSET = DPPIC_CHENSET_CH0_Msk;

    // PERI PD
    NRF_SAADC->SUBSCRIBE_START = (0<<SAADC_SUBSCRIBE_START_CHIDX_Pos) | SAADC_SUBSCRIBE_START_EN_Msk;
    NRF_PPIB21->PUBLISH_RECEIVE[0] = (0<<PPIB_PUBLISH_RECEIVE_CHIDX_Pos) | PPIB_PUBLISH_RECEIVE_EN_Msk;
    NRF_DPPIC20->CHENSET = DPPIC_CHENSET_CH0_Msk;
  

The following example shows how to create a PPIB connection between the TIMER10 compare event in the RADIO PD and the COMP start task in LP PD. The two PPI systems must be connected through PPIB instances PPIB21 and PPIB22 in PERI PD. These PPIB instances are not connected to any peripheral, only to the PPIB instances in RADIO and LP power domains. PERI PD acts as a central system that connects the two systems by means of local PPIB and DPPIC instances. This allows scaling to larger PPI systems, since multiple PPI systems can be interconnected through a central PPI system. DPPI channel 0 is used for internal RADIO PD connections, channel 1 is used by LP PD, and channel 5 is used by PERI PD. It is important that same DPPI channels are used within a power domain, but across domains the DPPI channel number does not matter.

    // RADIO PD
    NRF_TIMER10->PUBLISH_COMPARE[0] = (0<<TIMER_PUBLISH_COMPARE_CHIDX_Pos) | TIMER_PUBLISH_COMPARE_EN_Msk;
    NRF_PPIB11->SUBSCRIBE_SEND[0] = (0<<PPIB_SUBSCRIBE_SEND_CHIDX_Pos) | PPIB_SUBSCRIBE_SEND_EN_Msk;
    NRF_DPPIC10->CHENSET = DPPIC_CHENSET_CH0_Msk;

    // LP PD
    NRF_COMP->SUBSCRIBE_START = (1<<LPCOMP_SUBSCRIBE_SAMPLE_CHIDX_Pos) | COMP_SUBSCRIBE_START_EN_Msk;
    NRF_PPIB30->PUBLISH_RECEIVE[0] = (1<<PPIB_PUBLISH_RECEIVE_CHIDX_Pos) | PPIB_PUBLISH_RECEIVE_EN_Msk;
    NRF_DPPIC30->CHENSET = DPPIC_CHENSET_CH1_Msk;

    // PERI PD
    NRF_PPIB21->PUBLISH_RECEIVE[0] = (5<<PPIB_PUBLISH_RECEIVE_CHIDX_Pos) | PPIB_PUBLISH_RECEIVE_EN_Msk;
    NRF_PPIB22->SUBSCRIBE_SEND[0] = (5<<PPIB_SUBSCRIBE_SEND_CHIDX_Pos) | PPIB_SUBSCRIBE_SEND_EN_Msk;
    NRF_DPPIC20->CHENSET = DPPIC_CHENSET_CH5_Msk;