Flag Register
Among the internal registers of the CPU, there is a special register (for different processors, the number and structure may be different) has the following three functions.
Used to store some execution results of related instructions;
Used to provide behavioral basis for the CPU to execute related instructions;
It is used to control the related working mode of the CPU.
This special register is called flag register (flag) in 8086CPU.
The flag register of 8086CPU has 16 bits, the information stored in it is usually called PSW-Program Status Word (PSW-Program Status Word)
The flag register works bit by bit, and each bit of it has a special meaning and records specific information
Reference: <<Assembly Language>> Wang Shuang