Design a mod-7 up-down counter. The counter must count-up
when the input signal up is 1. Otherwise, the counter must
count-down. After reset, the counter must be initialized at
zero.
module updown_mod7(up, count, clk, rst);
input up, clk, rst;
output [2:0] count;up is the input signal that indicates when the
counter must count-up (1) or count-down (0).
clk is the clock signal.
rst is the synchronous reset signal.
count is the 3-bit output.