Quartech 9605 Product manual - Bcd Numbers
Page 8
PM9605 Revision 1, 9605 Version 36.1.1
BCD Numbers
Decimal
digit
BCD Bit
8 4 2 1
0
0 0 0 0
1
0 0 0 1
2
0 0 1 0
3
0 0 1 1
4
0 1 0 0
5
0 1 0 1
6
0 1 1 0
7
0 1 1 1
8
1 0 0 0
9
1 0 0 1
Figure 1.
Setup Mode Switch and LED assignments.
BCD stands for Binary Coded Decimal. The BCD numbering scheme is a
convenient way of using the binary number system to encode a decimal
number. The basic idea is to use a separate four bit binary number to
represent each individual digit of the decimal number. The table to the left
shows the possible combinations for a one digit decimal number. The bits
of the BCD number sum to equal the decimal digit, if each bit is weighted
as shown at the top of the table. For example, look at number 6:
0110
(0x8) + (1x4) + (1x2) + (0x1) = 6.
Also, for number 9:
1001
(1x8) + (0x4) + (0x2) + (1x1) = 9.
The 9605 uses BCD numbers to display some Setup Mode parameters.
The 10's digit is displayed on the third row (LEDs 9-12), and the 1's digit is
displayed on the fourth row(LEDs 13-16). For example, to set the Dialogue
file equal to 69, LEDs 10, 11, 13, and 16 must be red and all the rest of the
LEDs must be green.