www.pudn.com > noc.rar > switch.cpp

/*
 *  TU Eindhoven
 *  Eindhoven, The Netherlands
 *
 *  Name            :   switch.cpp
 *
 *  Author          :   A.S.Slusarczyk@tue.nl
 *
 *  Date            :   13-09-2003
 *
 *  Function        :   Crossbar switch with e-cube router
 *
 */

#include "switch.h"

// data multiplexing
void CROSSBAR3x3::crossbar_process()
{  
  bool c00, c01, c02, c10, c11, c12, c20, c21, c22;
  sc_uint<2> g0 = grant0.read(), g1 = grant1.read(), g2 = grant2.read();
  sc_bv zero(0);
    
  c00 = (g0==1);
  c01 = (g1==1);
  c02 = (g2==1);
  c10 = (g0==2);
  c11 = (g1==2);
  c12 = (g2==2);
  c20 = (g0==3);
  c21 = (g1==3);
  c22 = (g2==3);

  // data and req flow from requester to requested
  data_out_0.write(c00 ? data_in_0.read() : (c10 ? data_in_1.read() : ( c20 ? data_in_2.read() : zero)));
  data_out_1.write(c01 ? data_in_0.read() : (c11 ? data_in_1.read() : ( c21 ? data_in_2.read() : zero)));
  data_out_2.write(c02 ? data_in_0.read() : (c12 ? data_in_1.read() : ( c22 ? data_in_2.read() : zero)));

  req_out_0.write(c00 ? req_in_0.read() : (c10 ? req_in_1.read() : ( c20 ? req_in_2.read() : 0)));
  req_out_1.write(c01 ? req_in_0.read() : (c11 ? req_in_1.read() : ( c21 ? req_in_2.read() : 0)));
  req_out_2.write(c02 ? req_in_0.read() : (c12 ? req_in_1.read() : ( c22 ? req_in_2.read() : 0)));

  // ack flows from requested to requester
  ack_out_0.write(c00 ? ack_in_0.read() : (c01 ? ack_in_1.read() : ( c02 ? ack_in_2.read() : 0)));
  ack_out_1.write(c10 ? ack_in_0.read() : (c11 ? ack_in_1.read() : ( c12 ? ack_in_2.read() : 0)));
  ack_out_2.write(c20 ? ack_in_0.read() : (c21 ? ack_in_1.read() : ( c22 ? ack_in_2.read() : 0)));
}


// arbitration
void CROSSBAR3x3::arbiter_process()
{  
  bool c00, c01, c02, c10, c11, c12, c20, c21, c22, c0, c1, c2;
  sc_uint<2> a0=addr_0.read(), a1=addr_1.read(), a2=addr_2.read();
  sc_uint<2> g0 = grant0.read(), g1 = grant1.read(), g2 = grant2.read();
  sc_uint<2> rr = round_robin.read();
  bool rrinc = false;
    
  // who wants what?
  c0 = (conn_0.read()==true);
  c1 = (conn_1.read()==true);
  c2 = (conn_2.read()==true);
  c00 = c0 && (a0==1);
  c01 = c0 && (a0==2);
  c02 = c0 && (a0==3);
  c10 = c1 && (a1==1);
  c11 = c1 && (a1==2);
  c12 = c1 && (a1==3);
  c20 = c2 && (a2==1);
  c21 = c2 && (a2==2);
  c22 = c2 && (a2==3);
  
  if( g0 != 0 ){
    // output is busy - wait for the holder to release conn_x
    if( ((g0 == 1) && !c0) || ((g0 == 2) && !c1) || ((g0 == 3) && !c2) )
      g0 = 0;
  }
  else { // output if free - grant to requester with number equal to round_robin, or lowest number
    if( c00 && rr==0 ){
      rrinc = true; g0 = 1;
    }
    else if( c10 && rr==1 ){
      rrinc = true; g0 = 2;
    }
    else if( c20 && rr==2 ){
      rrinc = true; g0 = 3;
    }
    else
      g0 = ( c00 ? 1 : (c10 ? 2 : (c20 ? 3 : 0)) ); 
  }

  
  if( g1 != 0 ){
    if( ((g1 == 1) && !c0) || ((g1 == 2) && !c1) || ((g1 == 3) && !c2) )
      g1 = 0;
  }
  else {
    if( c01 && rr==0 ){
      rrinc = true; g1 = 1;
    }
    else if( c11 && rr==1 ){
      rrinc = true; g1 = 2;
    }
    else if( c21 && rr==2 ){
      rrinc = true; g1 = 3;
    }
    else
      g1 = ( c01 ? 1 : (c11 ? 2 : (c21 ? 3 : 0)) ); 
  }

  if( g2 != 0 ){
    if( ((g2 == 1) && !c0) || ((g2 == 2) && !c1) || ((g2 == 3) && !c2) )
      g2 = 0;
  }
  else {
    if( c02 && rr==0 ){
      rrinc = true; g2 = 1;
    }
    else if( c12 && rr==1 ){
      rrinc = true; g2 = 2;
    }
    else if( c22 && rr==2 ){
      rrinc = true; g2 = 3;
    }
    else
      g2 = ( c02 ? 1 : (c12 ? 2 : (c22 ? 3 : 0)) ); 
  }


  grant0.write(g0);
  grant1.write(g1);
  grant2.write(g2);
  rr_inc.write(rrinc);
}


void CROSSBAR3x3::round_robin_process()
{
  if( rr_inc.read() ){
    round_robin.write( round_robin.read()+1 );
  }
}