The difference between ( M0P_RTC->CR0 & 0x7faf ) != 0x4188 and ( M0P_RTC->CR0 & 0x4188 ) != 0x4188

一沙一世

The difference between ( M0P_RTC->CR0 & 0x7faf ) != 0x4188 and ( M0P_RTC->CR0 & 0x4188 ) != 0x4188 [Copy link]

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Why is it not written as if ( ( M0P_RTC->CR0 & 0x7faf ) !=0x4188 )

if ( ( M0P_RTC->CR0 & 0x4188) !=0x4188 )

damiaa

0x7faf ==》0111 1111 1010 1111

| | | | | | | | | | | | | | Bit to be judged

0x4188=》 0100 0001 1000 1000

| | | | The bit to be judged

The bits to be judged are different, that is, M0P_RTC->CR0 has these bits to be judged

There are more bits to be judged above, and all bits are related to the above results

The extra bits that are not to be judged have nothing to do with the result.