要求：经串口调试助手发送6个数后对这6个数进行排序，再在调试助手接收端显示排完序的数据
代码如下：
module cal(
input clk,
input rxf,
input txe,
input key,
input[7:0] datain,
output reg[7:0] dataout,
output over,
output reg wr,
output reg rd,
output reg SI
);
reg [24:0]sample;
reg sig_r0;
reg sig_r1;
wire rst;
reg clear_key;
reg last_key;
reg [7:0] memo[5:0];
integer i,j,m,n;
reg [4:0]state;
reg [7:0]buffer;
reg div_clk;
reg div_clk2;
initial begin
state <= 0;
wr <= 0;
rd <= 1;
SI <= 1;
end
task exchange(
inout[7:0] x,y
);
reg[7:0] temp;
begin
if(x<y)
begin
temp=x;
x=y;
y=temp;
end
end
endtask
always @(posedge clk)
begin
div_clk <= ~div_clk;
end
always @(posedge div_clk)
begin
div_clk2 <= ~div_clk2;
end
always @(posedge div_clk2)
begin
if(sample==120000)
begin
last_key <= key;
sample <= 0;
if(last_key == key)
begin
clear_key <= key;
end
end
else
sample <= sample+1;
end
always @ (posedge div_clk2)
begin
sig_r0 <= clear_key;
sig_r1 <= sig_r0;
end
assign rst = sig_r1 & (~sig_r0);
always @(posedge div_clk2)
if(rst)
begin
i=0;
j=0;
m=0;
n=0;
end
else
begin
case(state)
5'd0: begin
if(rxf == 0)begin
rd <= 0;
state <= 1;
end
end
5'd1: begin
if(m<6)
begin
memo[m] <= datain ;
m=m+1;
state <= 1;
end
else begin
rd <= 1;
state <= 2;
end
end
5'd2: begin
if(txe == 0)begin
if(i==6)
begin
i=6;
dataout <= memo[n];
n=n+1;
wr <= 1;
state <= 5'd3;
end
end
if(i<6)
for(i=0;i<6;i=i+1)
begin
for(j=0;j<5-i;j=j+1)
exchange(memo[j+1],memo[j]);
end
end
5'd3: begin
if(n<6)begin
wr <= 0;
state <= 5'd2;
end else begin
wr <= 0;
state <= 5'd4;
end
end
5'd4: begin
SI <= 0;
state <= 5'd5;
end
5'd5: begin
SI <= 1;
state <= 5'd0;
end
default:state <= 0;
endcase
end
assign data = (state==5'd3)?dataout:8'bzzzz_zzzz;
endmodule
烧录运行结果如下：
本人初学者，求大神指点错误
