Add Add - Samsung S3C8275X User Manual

S3C8275X/F8275X/C8278X/F8278X/C8274X/F8274X
ADD
— Add
ADD dst,src
dst ← dst + src
Operation:
The source operand is added to the destination operand and the sum is stored in the destination.
The contents of the source are unaffected. Two's-complement addition is performed.
Flags: C: Set if there is a carry from the most significant bit of the result; cleared otherwise.
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, if both operands are of the same sign and the
result is of the opposite sign; cleared otherwise.
D: Always cleared to "0".
H: Set if a carry from the low-order nibble occurred.
Format:
opc
opc
opc
Examples: Given: R1 = 12H, R2 = 03H, register 01H = 21H, register 02H = 03H, register 03H = 0AH:
ADD
ADD
ADD
ADD
ADD
In the first example, destination working register R1 contains 12H and the source working register
R2 contains 03H. The statement "ADD R1,R2" adds 03H to 12H, leaving the value 15H in
register R1.
dst | src
src dst
dst src
→
R1,R2
→
R1,@R2
→
01H,02H
→
01H,@02H
→
01H,#25H
Bytes
2
3
3
R1 = 15H, R2 = 03H
R1 = 1CH, R2 = 03H
Register 01H = 24H, register 02H = 03H
Register 01H = 2BH, register 02H = 03H
Register 01H = 46H
INSTRUCTION SET
Cycles Opcode
(Hex)
4 02
6 03
6 04
6 05
6 06
Addr Mode
dst src
r r
r lr
R R
R IR
R IM
6-15