class spi_trans; 

  //Properties for Randomizing the MOSI 
  rand bit	      cmd;
  randc bit[24:0]  addr;
  rand bit[ 4:0]  cfgid;
  rand bit[31:0]  data[$];

  //Properties for Randomizing the pkt_sent process
  rand int		interval;
  rand int		half_sclk;


  constraint cstr {
    data.size() >=  1;
    data.size() <=  1;//not solid
    interval    <=  1000;
    interval    >=  0;
    half_sclk   <=  32;
    half_sclk   >=  4;
     //Select system_regfile
    (addr	>=  25'h000_0000   &&
     //addr	<=  25'h000_0037 &&
     int'(addr) <=  int'(25'h000_003B) - int'(data.size()*4) &&
     addr	!=  25'h000_0020   &&
     addr	!=  25'h000_0024)  ||
    (addr	==  25'h000_0040)  ||
     //Select instruction SRAMs    8192X32bit 32KB
    (addr	>=  25'h010_0000 &&
     //addr	<=  25'h010_7FFF && 
     int'(addr) <=  25'h010_8003 - data.size()*4)               ||
     //Select data SRAMs           8192X32bit 32KB
    (addr	>=  25'h020_0000 &&
     //addr	<=  25'h020_7FFF &&
     int'(addr) <=  25'h020_8003 - data.size()*4)               ||
     //Select awg_regfile
    (addr	>=  25'h030_0000 &&
     //addr	<=  25'h030_001F &&
     int'(addr) <=  int'(25'h030_0023) - int'(data.size()*4))   ||
    (addr	>=  25'h030_0098 &&
     //addr	<=  25'h030_00A3 &&
     int'(addr) <=  int'(25'h030_00A7) - int'(data.size()*4))   ||
    (addr	>=  25'h030_0100 &&
     //addr	<=  25'h030_0123 &&
     int'(addr) <=  int'(25'h030_0127) - int'(data.size()*4))   ||
    (addr	>=  25'h030_0128 &&
     //addr	<=  25'h030_0137 &&
     int'(addr) <=  int'(25'h030_013B) - int'(data.size()*4))   ||
     //Select envelope ID SRAMs    64X32bit 256B 
    (addr	>=  25'h040_0000 &&
     //addr	<=  25'h040_00FF &&
     int'(addr) <=  25'h040_0103 - data.size()*4)               ||
     //Select envelope data SRAMs  8192X32bit 32KB
    (addr	>=  25'h050_0000 &&
     //addr	<=  25'h050_7FFF &&
     int'(addr) <=  25'h050_8003 - data.size()*4)               ||
     //Select dac_regfile
    (addr	>=  25'h060_0000 &&
     //addr	<=  25'h060_0073 &&
     int'(addr) <=  int'(25'h060_0077) - int'(data.size()*4))   ||
     //Select mcu_regfile
    (addr	>=  25'h070_0000 &&
     //addr	<=  25'h070_01F &&
     int'(addr) <=  int'(25'h070_0023) - int'(data.size()*4))   ||
    (addr	>=  25'h070_0040 &&
     //addr	<=  25'h070_00A7 &&
     int'(addr) <=  int'(25'h070_00AB) - int'(data.size()*4))   ||
     //Select DBG SRAMs            256X128bit  4KB
    (addr	>=  25'h190_0000 &&
     //addr	<=  25'h190_0FFF &&
     int'(addr) <=  25'h190_1003 - data.size()*4)               ||
     //Select intpll_regfile
    (addr	>=  25'h1f0_0000 &&
     //addr	<=  25'h1f0_0057 &&
     int'(addr) <=  int'(25'h1f0_005B) - int'(data.size()*4))   ;             
 }

  function new();
  endfunction

  extern function bit  compare(spi_trans rhs_);
  extern function void print(integer fid);
  extern function void unpack(ref bit stream[$]);
  extern function void pack(bit stream[$]);

endclass : spi_trans 



function bit spi_trans::compare(spi_trans rhs_);
  bit 		result=1'b1;
  int		i=0;

  result = ((cmd   == rhs_.cmd) &&
	    (addr  == rhs_.addr) &&
	    (cfgid == rhs_.cfgid));

  if(this.data.size() != rhs_.data.size()) begin
    $display("data_sizes are different");
    result = 1'b0;
  end
  else 
    for(i=0;i<data.size();i++)begin
    	if(data[i] != rhs_.data[i])
	  result = 1'b0;
    end

  return result;
endfunction : compare


function void spi_trans::print(integer fid);
  int i=0;
  if(!cmd)$fwrite(fid,"----------ONE-PKT-DRIVEN----------\n");
  else    $fwrite(fid,"---------ONE-PKT-COLLECTED--------\n");
  $fwrite(fid,"cmd:\t%h\n",cmd);
  $fwrite(fid,"addr:\t%h\n",addr);
  $fwrite(fid,"cfgid:\t%h\n",cfgid);
  for(i=0;i<data.size();i++)begin
    $fwrite(fid,"data[%2d]='h%h\n",i,data[i]);
  end
endfunction : print


function void spi_trans::unpack(ref bit stream[$]);
  int i=0,j=0;

  stream[0]=cmd;

  for(i=0;i<25;i++)
    stream[i+1] = addr[24-i];

  for(i=0;i<5;i++)
    stream[i+26]= cfgid[4-i];

  stream[31]=0;
  
  for(i=0;i<data.size();i++)begin
    //$display("i=%2d,datai=%b",i,data[i]);
    for(j=0;j<32;j++)begin
      stream[32+i*32+j]=data[i][31-j];
      //$display("i=%2d,j=%2d,streamij=%b",i,j,stream[32+i*32+j]);
    end
  end

endfunction

function void spi_trans::pack(bit stream[$]);
  int i=0;
  bit[31:0]	data_temp=32'b0;

  cmd = stream.pop_front();

  for(i=0;i<25;i++)
    addr[24-i] = stream.pop_front();

  for(i=0;i<5;i++)
    cfgid[4-i] = stream.pop_front();

  //reserved
  stream.pop_front();
  
  while(stream.size()>0)begin
    for(i=0;i<32;i++)
      data_temp[31-i] = stream.pop_front();
    data.push_back(data_temp);
  end
endfunction