MSP430: What does P1OUT=4, P1OUT |=4, P1OUT &-=~8 mean?

First of all, msp430 does not have a P0 port, so let's use the P1 port to explain P1OUT = 4; P1.2 pin outputs a high level, and the rest of the P1 pins output a low level; P1OUT |= 4; P1.2 is set to a high level, and the rest of the P1 pins remain unchanged; P1OUT &= ~8; that is, P1OUT &= 0xf7, P1.3 is set to a low level, and the rest of the P1 pins remain unchanged; | is the OR operator, & is the AND operator, please refer to the C language application operator section for details!

If there is no P0 port, just treat P0 as P1 and explain P1OUT=4=0100; so P1.0, P1.1, P1.3 input P1.2 output P1OUT |=4=0100; so P1.2 output P1OUT &-=~8=-(1000)=0111; P1.3 input may not be correct. This is my own understanding. I have just read the book, so I hope experts can give me some advice. The following is a detailed explanation of AND or OR. Please take a closer look. This is what I organized when I was studying. (1) The & is often used to test whether a certain bit is 1 or 0. The following program tests whether the fourth bit of the variable flag is 1 or 0. #define TEST 8 main() { int flag; ...; if ((flag&TEST)!=0) { printf("fourth bit is set"); } } Note that the logical operator has a lower priority than the relational operator and must be enclosed in parentheses. Bitwise AND is also often used to clear certain bits of the operand or to keep certain bits: a=a&0xffff clears the upper 16 bits and keeps the lower 16 bits. (2) Bitwise OR is often used to set a bit in an identifier to 1 #define SET 8 main() { int flag; ...; flag=flag | SET; //Same as flag |=SET if((flag & TEST)!=0) { printf("flag is set") } } (3) The negation operator is often used with the bitwise AND operation to turn off a bit. x=8; flag=flag &~x; //flag &=~x will turn off the fourth bit of flag. (4) Shift operators << , >> Shift operations are often used to multiply or divide by powers of 2. x=y<<1; This statement shifts y left by one bit and then assigns it to x. The decimal value of x is equal to the value of y multiplied by 2. Similarly, shifting right by one bit is equal to the value of y divided by 2.