Function of BCD adder and diagram

Function of BCD adder and diagram

Binary coded (BCD) full adder performs the addition of two decimal numbers (A0±A3, B0±B3). The look ahead generates the BCD carry terms internally, allowing the 'F583 to then do BD addition correctly. For BCD numbers 0 through 9 at A and B inputs, the BCD sum forms at the output. In the addition of two BCD numbers totaling a number greater than 9, a valid BCD number and a carry will result. 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, An or Bn, 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.