Samsung KS57C2308 manual ADC and SBC Instruction Skip Conditions, Adc A,@Hl, Sbc A,@Hl

KS57C2308/P2308/C2316/P2316 SAM47 INSTRUCTION SET

ADC and SBC Instruction Skip Conditions

The instructions “ADC A,@HL” and “SBC A,@HL” can generate a skip signal, and set or clear the carry flag, when they are executed in combination with the instruction “ADSA,#im”.

If an “ADSA,#im” instruction immediately follows an “ADC A,@HL” or “SBC A,@HL” instruction in a program sequence, the ADS instruction does not skip the instruction following ADS, even if it has a skip function. If, however, an “ADC A,@HL” or “SBC A,@HL” instruction is immediately followed by an “ADSA,#im” instruction, the ADC (or SBC) skips on overflow (or if there is no borrow) to the instruction immediately following the ADS, and program execution continues. Table 5-3 contains additional information and examples of the “ADC A,@HL” and “SBC A,@HL” skip feature.

Table 5-3. Skip Conditions for ADC and SBC Instructions

Sample		If the result of	Then, the execution	Reason
Instruction Sequences		instruction 1 is:	sequence is:
ADC A,@HL	1	Overflow	1, 3, 4	ADS cannot skip
ADS A,#im	2			instruction 3, even if it
xxx	3	No overflow	1, 2, 3, 4	has a skip function.
xxx	4
SBC A,@HL	1	Borrow	1, 2, 3, 4	ADS cannot skip
ADS A,#im	2			instruction 3, even if it
xxx	3	No borrow	1, 3, 4	has a skip function.
xxx	4

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