串并转换

spps.v

module spps (clk, rst_n, en, si, po, flag, load, pi, so, sign ); 
    input clk; 
    input rst_n; 
    input en; 
    input si; 
    input load; 
    input flag; 
    input [7:0] pi; 
    output reg so; 
    output reg [7:0] po; 
    output reg sign; 
    reg [7:0] r; 


    always@(posedge clk )   
        if(flag)    
            begin      
                if(~rst_n)        
                    begin        
                        r <= 16'h0;        
                    end      
                else        
                    begin        
                        r = {r, si};              
                        if(si||~si)       
                            begin          
                                po = (en) ? r :8'h0;         
                                sign=(en)?1'b1:1'b0;       
                            end      
                        else       
                            begin       
                                po=8'hxxxxxxxx;       
                                sign=1'b0;       
                            end        
                    end    
            end    
        else 
            begin       
                if(~rst_n)   //锟斤拷锟诫串锟斤拷
                    begin         
                        r <= 8'h0;   //锟斤拷锟斤拷锟斤拷位锟脚猴拷rst_n为锟酵碉拷平锟斤拷锟斤拷0000        
                    end       
                else if(load)   //锟斤拷锟斤拷load锟脚猴拷为锟竭碉拷平锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟脚猴拷
                    begin          
                        r <= pi;   //锟斤拷锟斤拷锟斤拷值r锟斤拷锟斤拷
                    end       
                else    //锟斤拷锟斤拷load为锟酵碉拷平锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷
                    begin 
                        r <= {r, 1'bx}; //锟斤拷位锟侥达拷锟斤拷锟斤拷实锟街ｏ拷锟斤拷锟斤拷r锟斤拷锟斤拷锟斤拷so锟斤拷锟斤拷锟斤拷r锟窖撅拷锟斤拷锟斤拷锟剿碉拷位锟斤拷为x
                        if(r[7]||~r[7])   //锟叫讹拷r锟侥达拷锟斤拷锟角凤拷锟窖撅拷全锟斤拷锟斤拷锟斤拷为x                 
                            begin                  
                                so = r[7];                   
                                if(r[6]||~r[6])  //锟斤拷r2没锟斤拷锟斤拷锟斤拷之前sign为0                    
                                    sign=1'b0;                   
                                else    //锟斤拷r3锟秸革拷锟斤拷锟斤拷锟斤拷瞬锟戒，sign锟斤拷为1                    
                                    sign=1'b1;                 
                            end               
                        else                
                            begin                 
                                so=1'bx;    //没锟斤拷锟脚猴拷锟斤拷锟斤拷时so锟斤拷为锟斤拷锟斤拷态
                                sign=0;   //锟斤拷志锟斤拷锟铰癸拷锟斤拷
                            end                        
                    end    
            end
endmodule