Condition Code Computation - Motorola MC68030 User Manual

3.3.1 Condition Code Computation

Most operations take a source operand and a destination operand, compute, and store the
result in the destination location. Single-operand operations take a destination operand,
compute, and store the result in the destination location. Table 3–12 lists each instruction
and how it affects the condition code bits.
Table 3-12. Condition Code Computations (Sheet 1 of 2)
Operations
ABCD
ADD, ADDI, ADDQ
ADDX
AND, ANDI, EOR, EORI,
MOVEQ, MOVE, OR, ORI
CLR, EXT, NOT, TAS, TST
CHK
CHK2, CMP2
SUB, SUBI, SUBQ
SUBX
CAS, CAS2, CMP, CMPI,
CMPM
DIVS, DUVI
MULS, MULU
SBCD, NBCD
NEG
NEGX
MOTOROLA
X N Z V C
* U ? U ? C =-Decimal Carry
Z =-Z Λ Rm Λ . . . Λ R0
? V = Sm Λ Dm Λ Rm V Sm Λ Dm Λ Rm
* * * ?
C = Sm Λ Dm V Rm Λ Dm V Sm Λ Rm
? V = Sm Λ Dm Λ Rm V Sm Λ Dm Λ Rm
* * ? ?
C = Sm Λ Dm V Rm Λ Dm V Sm Λ Rm
Z = Z Λ Rm Λ . . . Λ R0
— * * 0 0
— * U U U
— U ? U ? Z = (R = LB) V (R = UB)
C = (LB < = UB) Λ (IR < LB) V (R > UB))
V = (UB <LB) Λ (R >UB) Λ (R <LB)
? V = Sm Λ Dm Λ Rm V Sm Λ Dm Λ Rm
* * * ?
C = Sm Λ Dm V Rm Λ Dm V Sm Λ Rm
? V = Sm Λ Dm Λ Rm V Sm Λ Dm Λ Rm
* * ? ?
C = Sm Λ Dm V Rm Λ Dm V Sm Λ Rm
Z = Z Λ Rm Λ . . . Λ R0
? V = Sm Λ Dm Λ Rm V Sm Λ Dm Λ Rm
— * * ?
C = Sm Λ Dm V Rm Λ Dm V Sm Λ Rm
— * * ? 0 V = Division Overflow
— * * ? 0 V = Multiplication Overflow
* U U ? C = Decimal Borrow
Z = Z Λ Rm Λ . . . Λ R0
? V = Dm Λ Rm
* * * ?
C = Dm V Rm
? V = Dm Λ Rm
* * ? ?
C = Dm V Rm
Z = Z Λ Rm Λ . . . Λ R0
MC68030 USER'S MANUAL
Instruction Set Summary
Special Definition
3-15