BCD to Excess-3 Encoder

The module receives a BCD digit on i_bcd. For values 0 to 9, o_valid is '1' and o_xs3 is i_bcd + 3. For invalid combinations 10 to 15, o_valid is '0' and o_xs3 is 0000.

Behaviour

• pure combinational logic;
• no clock;
• stable output for every input combination.