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Atlas #544099 and #447399 DCC Decoders
9
Atlas Model Railroad Co., Inc.
Converting the Binary Values of Individual
Bits within a Configuration Variable into an
Equivalent Decimal Value for the Entire CV
Reasons for Setting and Clearing the Individual Bits of a
Configuration Variable
In order to make a DCC decoder perform in the manner that you wish it
to perform, one must sometimes set or clear individual bits of a CV. To
program a DCC decoder using a DCC system that allows only the
writing of decimal values into CVs (such as the Atlas Master
Commander), it is first necessary to convert the values of all the
individual bits of that CV that are to be set to the binary value 1 into their
equivalent decimal values. It is then necessary to add together all of
these equivalent decimal values.
Procedure for Converting Individual CV Bit Values into a
Decimal Equivalent Value for the CV
The following table illustrates how to calculate the decimal value that
must be written into a CV in order to set and/or clear a specified set of
individual bits within that CV.
Bit
Number
Decimal
Equivalent
Decimal
Values for
CV
Calculation
0 1
1 2
2 4
3 8
4 16
5 32
6 64
Each bit of a CV that is to be set to the binary
value “1” can be represented by the equivalent
decimal number shown in the second column of
this table. To determine the equivalent decimal
value to be written into the CV, first write down
in column 3 of this table the decimal equivalent
values of all the bits of the CV that are to be set
to a binary 1. Write nothing in column 3 for
each bit of the CV that is to be cleared, i.e., set
to a binary 0. Then add up all the numbers that
you have written down in column 3. The sum
that you get is the equivalent decimal value that
you need to write into the CV.
7 128
SUM: