Question

Write a VHDL module that implements a combinational dircuit that indicates the number of days in a given month. Notes: Q4) .. The month input is a single port (4-bit number The Leap Year port indicate if it is a leap yeat . The outputs must be 4 separate ports .Invalid months shouid result in no outputs active. (5 marks) di 1緋 VHDL code paste here using fixed-uidth gth Fonr e consolas Et must be formanted and indented correstty otherwise it will not be lassessed. tio accidental 1ine wrapping THIS MUST BE TEXT - NOT AN IMAGE! !!

Answer 1

The logic behind the below code is that the circuit accepts the binary value of month and leap year as inputs and outputs the number of days in the month.

If the input month is of numbers 4,6,9,11(April,June,September,November) result of number of days is 30

If the input month is 2 (Feb) and input leap year is 0 number of days is displayed as 28

If the input month is 2(Feb) and input leap year is 1,number of days is 29.

If none of the above condition is true then the number of days is considered as 31.

Code

library ieee;

use ieee.std_logic_1164.all;

use ieee.numeric_std.all;

entity Number_Of_Days_In_Month is

   port (

      Month         : in unsigned(3 downto 0);

      LeapYear     : in std_logic;

      NumberOfDays: out unsigned(4 downto 0)

      );

end entity Number_Of_Days_In_Month;

architecture Number_Of_Days_In_Month_combinational of Number_Of_Days_In_Month is

   signal days_28 : std_logic;

   signal days_29 : std_logic;

   signal days_30 : std_logic;

   signal days_31 : std_logic;

begin

   days_30 <= '1' when Month= 9 or

                         Month= 4 or

                         Month = 6 or

                         Month = 11

                    else '0';

   days_28 <= '1' when Month= 2 and

                         LeapYear = '0'

                    else '0';

   days_29 <= '1' when Month = 2 and

                         LeapYear = '1'

                    else '0';

   days_31 <= '1' when days_30 = '0' and

                         days_28 = '0' and

                         days_29 = '0'

                    else '0';

   NumberOfDays <= to_unsigned(30,NumberOfDays'length) when days_30d = '1' else

to_unsigned(28,NumberOfDays'length) when days_28d = '1' else

to_unsigned(29,NumberOfDays'length) when days_29d = '1' else

to_unsigned(31,NumberOfDays'length) when days_31d = '1' else

to_unsigned(0,NumberOfDays'length);                  

end architecture Number_Of_Days_In_Month_combinational;