USER MANUAL Manual

Parallel Port Communications 7–5
Publication 2706-6.1
Using BCD Data Input
You can use the 16 data lines to input BCD data. The BCD
numbering system uses a group of four binary digits to represent a
single decimal digit. The following table shows the BCD value of
each data line.
Data Line D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
Data Line Value 8000 4000 2000 1000 800 400 200 100 80 40 20 10 8 4 2 1
For example, assume the following logic levels appear for each data
line. Adding the values of the individual data lines provides the value
being entered, 5545.
Data Line Logic Level Value
D0
D1
D2
D3
D4
D5
D6
D7
D8
D9
D10
D11
D12
D13
D14
D15
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
Logic 1
Logic 0
Logic 1
Logic 0
Logic 0
Logic 0
Logic 1
Logic 0
Logic 1
Logic 0
Logic 1
Logic 0
Logic 1
Logic 0
Logic 1
Logic 0
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
1
0
4
0
0
0
40
0
100
0
400
0
1000
0
4000
0
Sum of all values
5545