Omron SYSMAC CP Series Instruction & Reference Manual page 210

2 Instructions
Subtraction at (1)
Mi+1: CIO 201
0 9 5 8
Su+1: CIO 121
–
1 7 0 7
09583960+(100000000-17072641)
CY R+1: D101
1 9 2 5 1
Subtraction at (2)
0 0 0
Su+1: D101
–
9 2 5
00000000+(100000000-92511319)
CY R+1: D101
1 0 7 4
Final Subtraction Result
Mi+1: CIO 201
0 9 5 8
Su+1: D101
–
1 7 0 7
CY R+1: D101
1 0 7 4 8
Sample program
0.00
0.00
If the result of the subtraction is a negative number (Mi<Su or Mi+1, Mi <Su+1, Su), the result is output
as a 10's complement. The Carry Flag (CY) will turn ON. To convert the 10's complement to the true
number, a program which subtracts the result from 0 is necessary, as an input condition of the Carry
Flag (CY). The Carry Flag turning ON thus indicates that the result of the subtraction is negative.
2-174
S1: CIO 200
3 9 6 0
S2: CIO 120
2 6 4 1
R+1: D100
The Carry Flag (CY) is ON, so the result is subtracted from 0000 0000.
1 3 1 9
0 0 0 0 0
Su: D100
1 1 3 1 9
R+1: D100
8 8 6 8 1
Mi: CIO 200
3 9 6 0
Su: D100
2 6 4 1
The Carry Flag (CY) will be turned ON, so the actual number is
– 7,488,681. Because the content of D101 and D100 is negative, CY is
R+1: D100
used to turn ON CIO 21.00 to indicate this.
8 6 8 1
−B
When CIO 0.00 is ON in the following example, D110 is subtracted from
D100 as 4-digit BCD values, and the result will be output to D120.
D100
D110
D120
−BL
When CIO 0.00 is ON in the following example, D111 and D110 will be
subtracted from D101 and D100 as 8-digit BCD values, and the result will
D100
be output to D121 and D120.
D110
D120
CP1E CPU Unit Instructions Reference Manual(W483)