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INSTRUCTION SET
INC
— Increment
INC
dst
dst ← dst + 1
Operation:
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; cleared otherwise.
D: Unaffected.
H: Unaffected.
Format:
dst | opc
Examples:
Given: R0 = 1BH, register 00H = 0CH, and register 1BH = 0FH:
INC R0
INC 00H
INC @R0
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.
6-44
opc
dst
→ R0 = 1CH
→ Register 00H = 0DH
→ R0 = 1BH, register 01H = 10H
Bytes
Cycles
Opcode
1
4
r = 0 to F
2
4
4
S3C80A5B
Addr Mode
(Hex)
dst
rE
r
20
R
21
IR
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