8086 cpu标志积存器

Carry Flag (CF) - this flag is set to 1 when there is an unsigned overflow. For example when you add bytes 255 + 1 (result is not in range 0...255). When there is no overflow this flag is set to 0.

Zero Flag (ZF) - set to 1 when result is zero. For none zero result this flag is set to 0.

Sign Flag (SF) - set to 1 when result is negative. When result is positive it is set to 0. Actually this flag take the value of the most significant bit.

Overflow Flag (OF) - set to 1 when there is a signed overflow. For example, when you add bytes 100 + 50 (result is not in range -128...127).

Parity Flag (PF) - this flag is set to 1 when there is even number of one bits in result, and to 0 when there is odd number of one bits. Even if result is a word only 8 low bits are analyzed!

Auxiliary Flag (AF) - set to 1 when there is an unsigned overflow for low nibble (4 bits).

Interrupt enable Flag (IF) - when this flag is set to 1 CPU reacts to interrupts from external devices.

Direction Flag (DF) - this flag is used by some instructions to process data chains, when this flag is set to 0 - the processing is done forward, when this flag is set to 1 the processing is done backward.