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3
SEQUENCE PROGRAM EXECUTION
3.7.3 BCD (Binary Coded Decimal)
(1) BCD notation
BCD (binary coded decimal) is a numbering system in which one digit of DEC
(decimal) is expressed in BIN (binary).
Though it uses 4-bit representation like hexadecimal notation, it dose not use letters
A
Table3.6 shows the numeric expressions of BIN, BCD and DEC.
DEC (Decimal)
(2) BCD numeric expression
CPU module registers (data registers, link registers, etc.) consist of 16 bits.
In case of 16 bits, 0 to 9999 can be specified in BCD.
POINT
to F
.
H
H
Table3.6 Comparison of BIN, BCD, and DEC Numeric Expressions
BIN (Binary)
0
1
2
3
4
5
6
7
8
9
10
11
12
The CPU module regards value stored in BCD as BIN.
For example, if 8000 is stored in BCD, the CPU module performs operation,
regarding the value as -32768.
When performing arithmetic operation between values stored in BCD and any
values in the CPU module, use the operation instruction of the BCD.
3.7 Numeric Values which can be Used in Sequence Programs
BCD
(Binary Coded Decimal)
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1 0000
1011
1 0001
1100
1 0010
3.7.3 BCD (Binary Coded Decimal)
0
1
10
11
100
101
110
111
1000
1001
Carry
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2
3
4
5
6
7
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