pl4_lite_data_monitor.v

spi接口的vhdl实现

// 3. Inserts PC word when data follows non-PC word
// 4. Inserts payload resume if current burst is longer than SrcBurstLen
// 5. Drops reserved control or PC words followed by a PC word
// 6. Checks for idles following non EOP control word
// 7. Inserts EOP abort if if idle follows data on non-credit boundary
// 8. Drops Payload resume to same channel on credit boundaries
// 9. Inserts EOP abort if SOP or payload resume follows data on non-credit
//    boundary
// 10. Drops least significant byte if EOP is set to one credit valid
// 11. Drops the current EOP word if two EOP's are received back to back
//*****************************************************************************
always @(RDClk or negedge Reset_n)
begin: interprete_rdat
  if (!Reset_n)
  begin
    RDatDataIndex     <= #`TFF 'b0;
    CurrentAddress    <= #`TFF 'b0;
    FirstPC           <= #`TFF 1'b0;
    for (cnt = 0; cnt < `STORAGE_SIZE; cnt = cnt + 1)
    begin
      RDatData[cnt] <= {16{1'b0}};
      RCtlData[cnt] <= 'b0;
    end
  end
  else
  begin

    // If it is a training data word do not store it
    if (((InTraining == 1) && (RCtl == 1'b0)) ||
        ((RCtl == 1'b1) && (RDat == `TRAINING_CTL)));

    // Wait for a valid payload control word with SOP before storing any data.
    else if (FirstPC == 0)
    begin

      // If there is a valid payload control word followed by data, then
      // store the data and set the FirstPC flag
      if ((RDatData[RDatDataIndexMinus1][15] == 1) &&
          (RDatData[RDatDataIndexMinus1][12] == 1) &&
          (RCtlData[RDatDataIndexMinus1] == 1) && (RCtl == 0))
      begin
        FirstPC <= #`TFF 1'b1;
        RDatData[RDatDataIndex] <= #`TFF RDat;
        RCtlData[RDatDataIndex] <= #`TFF RCtl;
        CurrentAddress          <= #`TFF RDatData[RDatDataIndexMinus1][11:4];
        RDatDataIndex           <= #`TFF RDatDataIndexPlus1;
      end

      // If it is the first data sent, then store it and increment the
      // pointer RDatDataIndex.  Since it is the first data, strip any EOP
      // information
      else if (RDatDataIndex == 0)
      begin
        RDatData[RDatDataIndex] <= #`TFF {RDat[15], 2'b00, RDat[12:0]};
        RCtlData[RDatDataIndex] <= #`TFF RCtl;
        RDatDataIndex           <= #`TFF RDatDataIndexPlus1;
      end

      // Otherwise keep the pointer the same and write over the previous
      // value stored.  Since it is the first word, strip any EOP
      // information
      else
      begin
        RDatData[RDatDataIndexMinus1] <= #`TFF {RDat[15], 2'b00, RDat[12:0]};
        RCtlData[RDatDataIndexMinus1] <= #`TFF RCtl;
        RDatDataIndex                 <= #`TFF RDatDataIndex;
      end
    end

    // If it is a data word
    else if (RCtl == 0)
    begin

      // If the last word was a control word find out which type
      if (RCtlData[RDatDataIndexMinus1] == 1)
      begin

        // If the last control word was a reserved control word then change
        // it into a payload control word with the last address that data
        // was sent to (as per spec)
        if ((RDatData[RDatDataIndexMinus1][15] == 0) &&
            (RDatData[RDatDataIndexMinus1][12] == 1))
        begin
          $display("RDat Warning: Protocol Violation #1: Reserved control word followed by data. %0d ps", $time);
          RDatData[RDatDataIndexMinus1]  <= #`TFF {4'b1000, CurrentAddress,
                                                   4'b1111};
          RDatData[RDatDataIndex]        <= #`TFF RDat;
          RCtlData[RDatDataIndex]        <= #`TFF RCtl;
          RDatDataIndex                  <= #`TFF RDatDataIndexPlus1;
        end

        // If the last control word was a payload control word then store
        // the data value and update the current address
        else if (RDatData[RDatDataIndexMinus1][15] == 1)
        begin
          RDatData[RDatDataIndex] <= #`TFF RDat;
          RCtlData[RDatDataIndex] <= #`TFF RCtl;
          CurrentAddress          <= #`TFF RDatData[RDatDataIndexMinus1][11:4];
          RDatDataIndex           <= #`TFF RDatDataIndexPlus1;
        end

        // Otherwise insert a payload resume on the current address and
        // print a warning.  Then store the data
        else
        begin
          $display("RDat Warning: Protocol Violation #2: Data follows non payload control. %0d ps", $time);
          RDatData[RDatDataIndex]  <= #`TFF {4'b1000, CurrentAddress, 4'b1111};
          RCtlData[RDatDataIndex]  <= #`TFF 1'b1;
          RDatData[RDatDataIndexPlus1] <= #`TFF RDat;
          RCtlData[RDatDataIndexPlus1] <= #`TFF RCtl;
          RDatDataIndex                <= #`TFF RDatDataIndexPlus2;
        end
      end

      // If the last word was data then check for to see if the number of
      // bursts is greater then SrcBurstLen.  If it is insert a payload
      // control word and then store the next address.  Otherwise
      // just store the new data and increment the counter
      else
      begin
        if (BurstCnt >= SrcBurstLen)
        begin
          RDatData[RDatDataIndex]  <= #`TFF {4'b1000, CurrentAddress, 4'b1111};
          RCtlData[RDatDataIndex]  <= #`TFF 1'b1;
          RDatData[RDatDataIndexPlus1] <= #`TFF RDat;
          RCtlData[RDatDataIndexPlus1] <= #`TFF RCtl;
          RDatDataIndex                <= #`TFF RDatDataIndexPlus2;
        end
        else
        begin
          RDatData[RDatDataIndex] <= #`TFF RDat;
          RCtlData[RDatDataIndex] <= #`TFF RCtl;
          RDatDataIndex           <= #`TFF RDatDataIndexPlus1;
        end
      end
    end // (RCtl == 0)

    else // (RCtl == 1)
    begin

      // If the current word was a reserved control word then drop it
      if ((RDat[15] == 0) &&
          (RDat[12] == 1) &&
          (RCtl == 1))
        $display("RDat Warning : Protocol Violation #10. Reserved control word received. Control word will be dropped. %0d ps", $time);

      // If the current word is an idle
      else if (RDat[15:12] == 4'h0)
      begin

        if (RDat[11:4] != 8'h00)
          $display("RDat Warning : Protocol Violation #11. IDLE control word with non-zero channel received. %0d ps", $time);

        // If the last word was an idle replace last idle with current idle
        if ((RCtlData[RDatDataIndex] == 1) &&
            (RDatData[RDatDataIndex][15:4] == 12'h000))
        begin
          RDatData[RDatDataIndex] <= #`TFF RDat;
          RCtlData[RDatDataIndex] <= #`TFF RCtl;
        end

        // If the last word was training, store idle but don't increment
        // counter (Idle will be overwritten next cycle).
        else if (InTraining == 1)
        begin
          RDatData[RDatDataIndex] <= #`TFF RDat;
          RCtlData[RDatDataIndex] <= #`TFF RCtl;
        end

        // If the last word was a control word, check for EOP
        else if (RCtlData[RDatDataIndexMinus1] == 1)
        begin

          // If there was an EOP ignore the idle
          if (RDatData[RDatDataIndexMinus1][14:13] != 2'b00);

          // If there was no EOP then print error message
          else
          begin
            $display("RDat Warning: Protocol Violation #3. Idle follows non EOP control word. %0d ps", $time);
          end
        end// Last word was control word

        // If the last word was data check for a credit boundary
        else if (RCtlData[RDatDataIndexMinus1] == 0)
        begin

          // If there was a credit boundary and there is more than one data
          // word between the current word and the last payload control.
          if ((CreditBoundaryLast == 1) &&
              ((RCtlData[RDatDataIndexMinus2] == 0) ||
               (RDatData[RDatDataIndexMinus2][15] == 0)));  //  do nothing

          // If there was no credit boundary then display warning and change
          // the idle to an EOP abort.
          else
          begin
            $display("RDat Warning: Protocol Violation #4. Idle follows data on a non credit boundary. %0d ps", $time);
            RDatData[RDatDataIndex] <= 16'h2000;
            RCtlData[RDatDataIndex] <= 1'b1;
            RDatDataIndex <= RDatDataIndexPlus1;
          end
        end

        // if last word was undefined ignore current word
        else;
      end

      // If the last word was data check for EOP or a credit boundary before
      // storing the data
      else if (RCtlData[RDatDataIndexMinus1] == 0)
      begin

        // If there was no EOP then the end of data should have been on
        // a credit boundary.  If it was not then there will be an EOP abort
        // in the next control word.
        if (RDat[14:13] == 2'b00)
        begin

          // If it is on a credit boundary
          if (CreditBoundaryLast == 1)
          begin

            // If the control word is a payload resume to the same channel then
            // drop it.
            if ((RDat[15] == 1) && (RDat[12] == 0) &&
                (RDat[11:4] == CurrentAddress));

            // Otherwise store the control word
            else
            begin
              RDatData[RDatDataIndex] <= #`TFF RDat;
              RCtlData[RDatDataIndex] <= #`TFF RCtl;
              RDatDataIndex <= #`TFF RDatDataIndexPlus1;
            end
          end

          // If it is an SOP or a payload resume
          else
          begin
            $display("RDat Warning: Protocol Violation #5. Non EOP control word on a non-credit boundary. %0d ps", $time);
            RDatData[RDatDataIndex]      <= #`TFF {12'h200, RDat[3:0]};
            RDatData[RDatDataIndexPlus1] <= #`TFF {RDat[15], 2'b00, RDat[12:0]};
            RCtlData[RDatDataIndex]      <= #`TFF RCtl;
            RCtlData[RDatDataIndexPlus1] <= #`TFF RCtl;
            RDatDataIndex <= #`TFF RDatDataIndexPlus2;
          end
        end

        // There is an eop so store the control word.  Check the number of
        // bytes valid in the last data word and if it is only 1 byte, zero
        // out the least significant byte (7:0).  If the control word also
        // has PC data then strip it out and store it in the next buffer
        // slot
        else
        begin
          if ((RDat[15] == 1'b1) || (RDat[12] == 1'b1))
          begin
            RDatData[RDatDataIndex]      <= #`TFF {1'b0, RDat[14:13], 13'b0};
            RCtlData[RDatDataIndex]      <= #`TFF RCtl;
            RDatData[RDatDataIndexPlus1] <= #`TFF {RDat[15], 2'b00, RDat[12:0]};
            RCtlData[RDatDataIndexPlus1] <= #`TFF RCtl;
            RDatDataIndex <= #`TFF RDatDataIndexPlus2;
          end
          else
          begin
            RDatData[RDatDataIndex] <= #`TFF RDat;
            RCtlData[RDatDataIndex] <= #`TFF RCtl;
            RDatDataIndex <= #`TFF RDatDataIndexPlus1;
          end
          if (RDat[14:13] == 2'b11)
            RDatData[RDatDataIndexMinus1] <=
              #`TFF {RDatData[RDatDataIndexMinus1][15:8], 8'h00};
        end
      end

      // If the last word was an EOP then check the current word.  If it is
      // a EOP then drop the current word.  If it is any other control word
      // then store it
      else if (RDatData[RDatDataIndexMinus1][14:13] != 2'b00)
      begin

        // If the current word is an EOP then drop the EOP part (keep any
        // payload control part)
        if (RDat[14:13] != 2'b00)
        begin
          $display("RDat Warning: Protocol Violation #6. EOP control word follows EOP control word.  Second EOP will be dropped. %0d ps", $time);
          if ((RDat[15] == 1'b1) || (RDat[12] == 1'b1))
          begin
            RDatData[RDatDataIndex] <= #`TFF {RDat[15], 2'b00, RDat[12:0]};
            RDatDataIndex <= #`TFF RDatDataIndexPlus1;
          end
        end
        else
        begin
          RDatData[RDatDataIndex] <= #`TFF RDat;
          RCtlData[RDatDataIndex] <= #`TFF RCtl;
          RDatDataIndex <= #`TFF RDatDataIndexPlus1;
        end
      end

      // If the last word was a payload control word then check to see if
      // current word is payload control or reserved control.  If it is then
      // drop the last word (keep any EOP information) and store the current
      // word.  If it is not payload control then drop the last word and
      // insert a payload resume to the current address
      else if (RDatData[RDatDataIndexMinus1][15] == 1)
      begin
        if ((RDat[15] == 1) || (RDat[12] == 1))
        begin
          $display("RDat Warning: Protocol Violation #7. Payload control word followed by payload control word.  First word will be dropped (Only PC bits). %0d ps", $time);
          RDatData[RDatDataIndexMinus1] <=
            #`TFF {RDat[15], RDatData[RDatDataIndexMinus1][14:13], RDat[12:0]};
        end
        else
        begin
          RDatData[RDatDataIndexMinus1] <=
            #`TFF {4'b1000, CurrentAddress, 4'b1111};
          $display("RDat Warning: Protocol Violation #8. Payload control followed by non-data word. %0d ps", $time);
        end
      end // last control word was payload

      // If the last word was idle or training then store the control word
      else
      begin
        RDatData[RDatDataIndex] <= #`TFF RDat;