NRF52811-QCAA-R7 datasheet(151/444 Pages) NORDIC

151 / 444 page

Peripherals

Figure depicts the source code used for configuration and timing details in a sequence where only

sequence 0 is used and only run once with a new PWM duty cycle for each period.

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

= (PWM_LOOP_CNT_Disabled << 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 = 0;

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

NRF_PWM0->TASKS_SEQSTART[0] = 1;

To completely stop the PWM generation and force the associated pins to a defined state, a STOP task can

be triggered at any time. A STOPPED event is generated when the PWM generation has stopped at the

end of currently running PWM period, and the pins go into their idle state as defined in GPIO OUT register.

PWM generation can then only be restarted through a SEQSTART[n] task. SEQSTART[n] will resume PWM

generation after having loaded the first value from the RAM buffer defined in the SEQ[n].PTR register.

The table below indicates when specific registers get sampled by the hardware. Care should be taken

when updating these registers to avoid that values are applied earlier than expected.

4454_140 v1.0

151

NRF52811-QCAA-R7 bảng dữ liệu(PDF) 151 Page - Nordic Semiconductor