[embedded C foundation] Part 2: binary conversion and BCD coding

1 Preface

D Decimal system
B Binary system
H Hexadecimal

What is power ？
power ： Weight refers to the basic unit of each bit in the data .
For example, numbers in decimal 123, that 3 It's everybody , take a temporary measure 1,2 It's ten , take a temporary measure 10,1 It's a hundred , Right is 100.

Decimal system 10 Of i Power （i What's the number ）
Binary system 2 Of i Power
Others in the same way

2 Non decimal to decimal

3 Decimal to non decimal

3.1 Decimal to binary

The integer part is converted to binary number by “ except 2 Remainder ” Methods , That is, continuous division 2 And take the remainder as the result , Until business is 0, The remainder obtained is arranged in sequence from low to high, that is, the integer part of the converted binary number ;

For the decimal part , Then use “ ride 2 integer ” Methods , That is, the decimal part is used continuously 2 ride , Take the integer part of the first product as the highest bit , Until the required precision is achieved or the decimal part is 0 until .