Source code, anti-code, complement code, personal understanding, anti-Code complement

Source code, anti-code, complement code, personal understanding, anti-Code complement

Original code:

Binary Fixed-point notation, that is, the highest bit is the symbol bit, "0" indicates a positive number, "1" indicates a negative number, and the remaining bit indicates the value size.

The maximum digit of a positive number is 0.

The maximum digit of a negative number is 1.

Example:

Symbol bit value

+ 7 0 0000111

-7 1 0000111

Anti-code:

The reverse code of a positive number is the same as the original code, and there is no change

Negative Inverse code: it remains the same as the original symbol bit, and other values are reversed, that is, 0 is changed to 1, 1 is changed to 0.

Example:

Symbol bit value

+ 7 0 0000111

-7 1 1111000

Complement:

The positive complement code is the same as the original code, and there is no change

The complement of negative numbers is based on the anticode plus 1

Example:

Symbol bit value

+ 7 0 0000111

-7 1 1111001

 

Summary:

Why is the range of a byte-128 ~ 127

One byte is 8 bits, that is, 00000000 (8 bits)

To distinguish between positive and negative numbers, a computer occupies a sign bit to indicate positive and negative, so the maximum number can only represent 1111111 (7 digits ),

The binary 1111111 is converted to the 10th hexadecimal notation + 127.

 

Ask... I understand it, right?