Samsung 8-Bit CMOS Microcontroller, S3C9228/P9228 user manual INC Increment, INCdst

S3C9228/P9228 SAM88RCRI INSTRUCTION SET

INC — Increment

INCdst

Operation: dst ¨ dst + 1

The contents of the destination operand are incremented by one.

Flags:	C:	Unaffected.
	Z: Set if the result is "0"; cleared otherwise.
	S: Set if the result is negative; cleared otherwise.
	V: Set if arithmetic overflow occurred, that is dst value is +127(7FH) and result is –128(80H);
	D:	cleared otherwise.
		Unaffected.
	H:	Unaffected.

Format:
Bytes Cycles Opcode	Addr Mode
(Hex)	dst

dst opc

opc dst

1	4	rE	r
		r = 0 to F
2	4	20	R
	4	21	IR

Examples: Given: R0 = 1BH, register 00H = 0CH, and register 1BH = 0FH:

INC	R0	→	R0	= 1CH
INC	00H	→	Register 00H = 0DH
INC	@R0	→	R0	= 1BH, register 01H = 10H

In the first example, if destination working register R0 contains the value 1BH, the statement "INC R0" leaves the value 1CH in that same register.

The next example shows the effect an INC instruction has on register 00H, assuming that it contains the value 0CH.

In the third example, INC is used in Indirect Register (IR) addressing mode to increment the value of register 1BH from 0FH to 10H.

6-23