First, the status register
The PSW (Program Flag) program status word register is a 16-bit register, which is composed of a conditional code flag (FLAG) and control flag, as follows:
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Of DF IF TF SF ZF AF PF CF
Condition code:
1OF (Overflow Flag) overflow flag. Overflow is 1, otherwise 0.
2SF (Sign Flag) symbol. The result is a negative step 1, otherwise 0.
3ZF (Zero Flag) zero sign, the zf position 1 is 0 when the result is 0, otherwise 0.
4CF (Carry Flag) carry mark, carrying a time station 1, otherwise 0.
5AF (Auxiliary Carry Flag) Auxiliary Ground Sign, the 3rd (half byte) generated in the third bit (half byte) when the operation is recorded. When there is a carry 1, otherwise it will be 0.
6PF (Parity Flag) parity. The number of results in the result operand is an even number time 1, otherwise 0.
Control logo:
The 7DF (Direction Flag) direction flag controls the direction of the information in the string processing instruction.
8IF (Interrupt Flag) interrupt flag.
⑨TF (trap flag) trap sign.
Second, direct logo transfer
Command format machine code test conditions such as ...
Command format machine code test conditions such as ...
JC 72 c = 1 carry JNS 79 S = 0
JNC 73 C = 0 No in-line JO 70 o = 1 has overflow
JZ / JE 74 z = 1 zero / equal to JNO 71 o = 0 no overflow
JNZ / JNE 75 z = 0 is not zero / not equal to JP / JPE 7A P = 1 parity bit is an occasion
JS 78 s = 1 negative JNP / IPO 7B P = 0 odd bits are odd
Third, indirect logo transfer
Instruction format machine code test format, ...
JA / JNBE (more no sign number) 77 C or z = 0> above / not less than or equal to
JAE / JNB (more no sign number) 73 c = 0> = above or equal to / not less than
JB / JNAE (more no sign number) 72 c = 1 JBE / JNA (more no sign number) 76 C or z = 1 <= below or equal to / not higher than JG / JNLE (comparison with the number of symbols) 7f (Si or O) or z = 0> greater than / not less than or equal to JGE / JNL (comparison zone number) 7D S is different or o = 0> = greater than or equal to / not less than JL / JNGE (number of compared strips) 7C S is different or o = 1 JLE / JNG (Compare Sign Number) 7e (Si or O) or Z = 1 <= less than or equal to / not greater than Fourth, unconditional transfer command JMP Instruction format execution operating machine code Direct short transfer JMP Short (IP) ← (ip) 8-bit shift EB transfer range -128 to 127 bytes Direct proximal transfer JMP Near (ip) ← (IP) 16-bit shift E9 transfer to any of the segments Indirect transfer of JMP Word (IP) ← (Effective Address EA) FF Direct (far) transfer JMP FAR (IP) ← (offset address) (Cs) ← (segment address) EA Interior of the interior transfer JMP DWORD (IP) ← (EA) (Cs) ← (EA 2)
