Mitsubishi Electric MELSEC-Q00U(J)CPU User Manual page 498

Appendix 4.3
(1) Definition
BCD is a numeral system that uses four binary bits to represent the decimal digits 0 through 9.
The difference from hexadecimal is that BCD does not use letters A to F.
The following table lists the numeric representations in BIN, BCD, and DEC.
DEC (Decimal)
(2) Numeric representation in BCD
Each register (such as the data register, link register) in the CPU module consists of 16 bits.
Therefore, the numeric values can be stored in each register are those in the range between 0 to 9999 in BCD.
496
BCD (Binary-coded Decimal)
BIN (Binary)
0
1
2
3
4
5
6
7
8
9
10
11
12
BCD (Binary-coded Decimal)
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
0
1
10
11
100
101
110
111
1000
1001
Carry
1 0000
1 0001
1 0010