函数代码如下：
static void gpio_output_voltage_setup(void)
{
// Configure UICR_REGOUT0 register only if it is set to default value.
if ((NRF_UICR->REGOUT0 & UICR_REGOUT0_VOUT_Msk) ==
(UICR_REGOUT0_VOUT_DEFAULT << UICR_REGOUT0_VOUT_Pos))
{
NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Wen;
while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}
NRF_UICR->REGOUT0 = (NRF_UICR->REGOUT0 & ~((uint32_t)UICR_REGOUT0_VOUT_Msk)) |
(UICR_REGOUT0_VOUT_3V0 << UICR_REGOUT0_VOUT_Pos);
NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Ren;
while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}
// System reset is needed to update UICR registers.
NVIC_SystemReset();
}
}
