S3F84B8_UM_REV 1.00 6 INSTRUCTION SET6-326.3.20 DA — DECIMAL ADJUSTDA dstOperation: dst DA dstThe destination operand is adjusted to form two 4-bit BCD digits following an addition orsubtraction operation. For addition (ADD, ADC) or subtraction (SUB, SBC), the following tableindicates the operation performed. (The operation is undefined if the destination operand was notthe result of a valid addition or subtraction of BCD digits).Instruction CarryBefore DABits 4–7Value (Hex)H FlagBefore DABits 0–3Value (Hex)Number Addedto ByteCarryAfter DA0 0–9 0 0–9 00 00 0–8 0 A–F 06 00 0–9 1 0–3 06 0ADD 0 A–F 0 0–9 60 1ADC 0 9–F 0 A–F 66 10 A–F 1 0–3 66 11 0–2 0 0–9 60 11 0–2 0 A–F 66 11 0–3 1 0–3 66 10 0–9 0 0–9 00 = – 00 0SUB 0 0–8 1 6–F FA = – 06 0SBC 1 7–F 0 0–9 A0 = – 60 11 6–F 1 6–F 9A = – 66 1Flags: C: Set if there was a carry from the most significant bit; cleared otherwise (see table).Z: Set if result is “0”; cleared otherwise.S: Set if result bit 7 is set; cleared otherwise.V: Undefined.D: Unaffected.H: Unaffected.Format:Bytes Cycles Opcode(Hex)Addr Modedstopc dst 2 4 40 R4 41 IR
