74F583 Datasheet, PDF (2/5 Pages) NXP Semiconductors – 4-bit BCD adder

Functional Description
The ’F583 4-bit binary coded (BCD) full adder performs the
addition of two decimal numbers (A₀–A₃, B₀–B₃). The loo-
kahead generates the BCD carry terms internally, allowing
the 'F583 to then do BCD addition correctly. For BCD num-
bers 0 through 9 at A and B inputs, the BCD sum forms at
the output. In the addition of two BCD numbers totalling a
number greater than 9, a valid BCD number and a carry will
result.
Logic Diagram
For input values larger than 9, the number is converted
from binary to BCD. Binary to BCD conversion occurs by
grounding one set of inputs, A_n or B_n, and applying any 4-
bit binary number to the other set of inputs. If the input is
between 0 and 9, a BCD number occurs at the output. If
the binary input falls between 10 and 15, a carry term is
generated. Both the carry term and the sum are the BCD
equivalent of the binary input. Converting binary numbers
greater than 16 may be achieved through cascading
'F583s.
Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.
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