nrf52832 nrf_temp_init and nrf_temp_read

[lilealyh]

hi 

     I am a beginner,i have two questions.

1、when i use the nrf52832 to read the inner temperature,i find the nrf_temp_init function is :

static __INLINE void nrf_temp_init(void)
{
*(uint32_t *) 0x4000C504 = 0;
}

i am confuse why not is *(uint32_t *) 0x4000C508 = 0;because i see the document the TEMP offset is 0x508

2、could explain the function

static __INLINE int32_t nrf_temp_read(void)
{
return ((NRF_TEMP->TEMP & MASK_SIGN) != 0) ? (NRF_TEMP->TEMP | MASK_SIGN_EXTENSION) : (NRF_TEMP->TEMP);
}

i do not understand why NRF_TEMP->TEMP & MASK_SIGN and NRF_TEMP->TEMP | MASK_SIGN_EXTENSION

thank you replay

lilealyh

[Jørgen Holmefjord]

Hi,

Both these register writings are related to nRF51822 PAN workarounds. Please have a look at PAN-31 and PAN-28 in the nRF51822 PAN document. For nRF52832, these lines should not have any effect.

MASK_SIGN and MASK_SIGN_EXTENSION is used to fill the whole registers with the correct sign if measured value is negative, as negative values are not correctly represented.

Best regards,
Jørgen

[lilealyh]

Before I just see the nrf52832 pdf,not see the 51822,so confused with that function,Now I understand why it is.

Thanks very much!