Introduction - If you have any usage issues, please Google them yourself
Design of a decimal counter module, input port, including the reset up_enable clk, output port for the count and bcd, when reset is active (low), the bcd and count output cleared up_enable active (high), count module starts counting the (the CLK pulse number), the BCD count output when the count 9, the count output of the high level, the time of a pulse (a clk cycle with " bcd = 9" when aligned)