Omron CPM1 - PROGRAMING MANUAL 02-2001 Programming Manual page 478

BCD Calculation Instructions
7-21-5 BCD MULTIPLY – MUL(32)
Limitations
460
The first and second subtractions for this diagram are shown below using exam-
ple data for 201 and DM 0100.
Note The actual SUB(31) operation involves subtracting Su and CY from 10,000 plus
Mi. For positive results the leftmost digit is truncated. For negative results the
10s complement is obtained. The procedure for establishing the correct answer
is given below.
First Subtraction
IR 201
DM 0100 – 3452
CY
HR 10
CY
Second Subtraction
0000
HR 10 –7577
CY –0
HR 10 2423
CY 1
In the above case, the program would turn ON HR 1100 to indicate that the value
held in HR 10 is negative.
Ladder Symbols
MUL(32)
Md
Mr
R
DM 6144 to DM 6655 cannot be used for R.
Address Instruction
00000 LD
00001 OUT TR
00002 CLC(41)
00003 @SUB(31)
DM
HR
00004 AND
00005 CLC(41)
00006 @SUB(31)
#
HR
HR
00007 LD TR
00008 LD
00009 OR HR
00010 AND LD
00011 OUT HR
1029
– 0
7577 (1029 + (10000 – 3452))
1 (negative result)
(0000 + (10000 – 7577))
(negative result)
@MUL(32)
Md
Mr
R
Section
Operands
00002
0
201
0100
10
25504
0000
10
10
0
25504
1100
---
1100
Operand Data Areas
Md: Multiplicand (BCD)
IR, SR, AR, DM, HR, TC, LR, #
Mr: Multiplier (BCD)
IR, SR, AR, DM, HR, TC, LR, #
R: First result word
IR, SR, AR, DM, HR LR
7-21