what does this code mean/does ADC->ADC_IDR=~(1<<27); ?

ADC->ADC_IDR=~(1<<27);

it looks to me like it is setting some interrupt for the analog pin and it is assigning something.

I wonder what it does. I am looking at some codes to read the analog pin on Ardino Due

and send the reading every 1 us to a buffer / RAM

I think that 1 us is the top speed for Due.

and what would be the difference with similar code

ADC->ADC_IER=1<<27;

those are good codes they compile with no errors but only on Due.

Why have you started a new thread about the same code? Why are YOU not reading the damned data sheet? ALL your questions are answered there.

the data sheet does not explain what for example ~(1<<27) means

it only says that ADC_IER is Interrupt Enable Register

But I have no idea that the code ADC->ADC_IDR=~(1<<27); ? does.

Bitwise complement operator ~

Bitwise compliment operator is an unary operator (works on only one operand). It changes 1 to 0 and 0 to 1. It is denoted by ~.

1<<27 is the single digit 1 left-shifted by 27 places. I’m not going to type out 27 zeroes but it will give you a value that looks something like 00010000000…

Add the ~ and your value looks like 111011111111…