用Verilog 实现自动售货机_自动售饮料机，饮料2.5元，可以投0.5和1元，设找零功能，设计一个状态

功能介绍：本次的代码是一个售卖2.5元的饮料机，投币只能投0.5元和1元的硬币，投币达到2.5元时自动出饮料，投币3元时，会出饮料和找零0.5元。部分代码如下：`
always @(posedge clk or negedge rst_n) begin
if (!rst_n) curr_state <=S0;
else curr_state <=#1 next_state;
end
always @(one,half,curr_state) begin
case(curr_state)

S0:begin
if (half) next_state = S1;
else if (one) next_state = S2;
else next_state = S0;

end

S1:begin
if (half) next_state = S2;
else if (one) next_state = S3;
else next_state = S1;

end

S2:begin
if (half) next_state = S3;
else if (one) next_state = S4;
else next_state = S2;

end

S3:begin
if (half) next_state = S4;
else if (one) next_state = S5;
else next_state = S3;

end

S4:begin
if (half) next_state = S5;
else if (one) next_state =S6;
else next_state = S4;

end

S5:begin
next_state = S0;

end

S6:begin
next_state = S0;

end

default next_state = S0;

endcase

end
assign out = ((curr_state == S5)|| (curr_state == S6)) ?1:0;
assign cout = (curr_state ==S6) ? 1:0;
`