Incw Increment Word - Samsung S3C80A5B User Manual

S3C80A5B
INCW
— Increment Word
INCW dst
dst ← dst + 1
Operation:
The contents of the destination (which must be an even address) and the byte following that location
are treated as a single 16-bit value that is 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:
opc
Examples: Given: R0 = 1AH, R1 = 02H, register 02H = 0FH, and register 03H = 0FFH:
INCW
INCW
In the first example, the working register pair RR0 contains the value 1AH in register R0 and 02H in
register R1. The statement "INCW RR0" increments the 16-bit destination by one, leaving the value
03H in register R1. In the second example, the statement "INCW @R1" uses Indirect Register (IR)
addressing mode to increment the contents of general register 03H from 0FFH to 00H and register
02H from 0FH to 10H.
NOTE: A system malfunction may occur if you use a Zero (Z) flag (FLAGS.6) result together with an INCW
instruction. To avoid this problem, we recommend that you use INCW as shown in the following
example:
LOOP:
dst
→ R0 = 1AH, R1 = 03H
RR0
→ Register 02H = 10H, register 03H = 00H
@R1
INCW RR0
LD R2,R1
OR R2,R0
JR NZ,LOOP
Bytes Cycles Opcode
2 8
8
INSTRUCTION SET
Addr Mode
(Hex) dst
A0 RR
A1 IR
6-45