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BINARY-CODED DECIMAL | Up
Neets Module 13-Introduction to Number Systems and Logic Circuits | Next
BCD Addition - Continued |
1-60
The BCD equivalent of 26410 is 001001100100BCD. To convert from BCD to decimal, simply reverse
the process as shown:
BCD Addition
The procedures followed in adding BCD are the same as those used in binary. There is, however, the
possibility that addition of BCD values will result in invalid totals. The following example shows this:
Add 9 and 6 in BCD:
The sum 11112 is the binary equivalent of 1510; however, 1111 is not a valid BCD number. You
cannot exceed 1001 in BCD, so a correction factor must be made. To do this, you add 610 (0110BCD) to the
sum of the two numbers. The "add 6" correction factor is added to any BCD group larger than 10012.
Remember, there is no 10102, 10112, 11002, 11012, 11102, or 11112 in BCD:
The sum plus the add 6 correction factor can then be converted back to decimal to check the answer.
Put any carries that were developed in the add 6 process into a new 4-bit word:
Now observe the addition of 6010 and 5510 in BCD:
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