NRF52811-QCAA-R7 datasheet(154/444 Pages) NORDIC

154 / 444 page

Peripherals

1, the playback stops after having played SEQ[1] only once, and both SEQEND[1] and LOOPSDONE are

generated (their order is not guaranteed in this case).

NRF_PWM0->PSEL.OUT[0] = (first_pin << PWM_PSEL_OUT_PIN_Pos) |

(PWM_PSEL_OUT_CONNECT_Connected <<

PWM_PSEL_OUT_CONNECT_Pos);

NRF_PWM0->ENABLE

= (PWM_ENABLE_ENABLE_Enabled << PWM_ENABLE_ENABLE_Pos);

NRF_PWM0->MODE

= (PWM_MODE_UPDOWN_Up << PWM_MODE_UPDOWN_Pos);

NRF_PWM0->PRESCALER

= (PWM_PRESCALER_PRESCALER_DIV_1 <<

PWM_PRESCALER_PRESCALER_Pos);

NRF_PWM0->COUNTERTOP = (16000 << PWM_COUNTERTOP_COUNTERTOP_Pos); //1 msec

NRF_PWM0->LOOP

= (1 << PWM_LOOP_CNT_Pos);

NRF_PWM0->DECODER

= (PWM_DECODER_LOAD_Common << PWM_DECODER_LOAD_Pos) |

(PWM_DECODER_MODE_RefreshCount << PWM_DECODER_MODE_Pos);

NRF_PWM0->SEQ[0].PTR = ((uint32_t)(seq0_ram) << PWM_SEQ_PTR_PTR_Pos);

NRF_PWM0->SEQ[0].CNT = ((sizeof(seq0_ram) / sizeof(uint16_t)) <<

PWM_SEQ_CNT_CNT_Pos);

NRF_PWM0->SEQ[0].REFRESH = 1;

NRF_PWM0->SEQ[0].ENDDELAY = 1;

NRF_PWM0->SEQ[1].PTR = ((uint32_t)(seq1_ram) << PWM_SEQ_PTR_PTR_Pos);

NRF_PWM0->SEQ[1].CNT = ((sizeof(seq1_ram) / sizeof(uint16_t)) <<

PWM_SEQ_CNT_CNT_Pos);

NRF_PWM0->SEQ[1].REFRESH = 0;

NRF_PWM0->SEQ[1].ENDDELAY = 0;

NRF_PWM0->TASKS_SEQSTART[0] = 1;

The decoder can also be configured to asynchronously load new PWM duty cycle. If the DECODER.MODE

the next PWM period.

The following figures provide an overview of each part of an arbitrary sequence, in various modes

(LOOP.CNT=0 and LOOP.CNT>0). In particular, the following are represented:

• Initial and final duty cycle on the PWM output(s)

• Chaining of SEQ[0] and SEQ[1] if LOOP.CNT>0

• Influence of registers on the sequence

• Events generated during a sequence

• DMA activity (loading of next value and applying it to the output(s))

4454_140 v1.0

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NRF52811-QCAA-R7 Datasheet(PDF) 154 Page - Nordic Semiconductor