OpenFPGA/openfpga_flow/benchmarks/iwls2005/ethernet/rtl/eth_receivecontrol.v

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//////////////////////////////////////////////////////////////////////
//// ////
//// eth_receivecontrol.v ////
//// ////
//// This file is part of the Ethernet IP core project ////
//// http://www.opencores.org/projects/ethmac/ ////
//// ////
//// Author(s): ////
//// - Igor Mohor (igorM@opencores.org) ////
//// ////
//// All additional information is avaliable in the Readme.txt ////
//// file. ////
//// ////
//////////////////////////////////////////////////////////////////////
//// ////
//// Copyright (C) 2001 Authors ////
//// ////
//// This source file may be used and distributed without ////
//// restriction provided that this copyright statement is not ////
//// removed from the file and that any derivative work contains ////
//// the original copyright notice and the associated disclaimer. ////
//// ////
//// This source file is free software; you can redistribute it ////
//// and/or modify it under the terms of the GNU Lesser General ////
//// Public License as published by the Free Software Foundation; ////
//// either version 2.1 of the License, or (at your option) any ////
//// later version. ////
//// ////
//// This source is distributed in the hope that it will be ////
//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
//// PURPOSE. See the GNU Lesser General Public License for more ////
//// details. ////
//// ////
//// You should have received a copy of the GNU Lesser General ////
//// Public License along with this source; if not, download it ////
//// from http://www.opencores.org/lgpl.shtml ////
//// ////
//////////////////////////////////////////////////////////////////////
//
// CVS Revision History
//
// $Log: eth_receivecontrol.v,v $
// Revision 1.5 2003/01/22 13:49:26 tadejm
// When control packets were received, they were ignored in some cases.
//
// Revision 1.4 2002/11/22 01:57:06 mohor
// Rx Flow control fixed. CF flag added to the RX buffer descriptor. RxAbort
// synchronized.
//
// Revision 1.3 2002/01/23 10:28:16 mohor
// Link in the header changed.
//
// Revision 1.2 2001/10/19 08:43:51 mohor
// eth_timescale.v changed to timescale.v This is done because of the
// simulation of the few cores in a one joined project.
//
// Revision 1.1 2001/08/06 14:44:29 mohor
// A define FPGA added to select between Artisan RAM (for ASIC) and Block Ram (For Virtex).
// Include files fixed to contain no path.
// File names and module names changed ta have a eth_ prologue in the name.
// File eth_timescale.v is used to define timescale
// All pin names on the top module are changed to contain _I, _O or _OE at the end.
// Bidirectional signal MDIO is changed to three signals (Mdc_O, Mdi_I, Mdo_O
// and Mdo_OE. The bidirectional signal must be created on the top level. This
// is done due to the ASIC tools.
//
// Revision 1.1 2001/07/30 21:23:42 mohor
// Directory structure changed. Files checked and joind together.
//
// Revision 1.1 2001/07/03 12:51:54 mohor
// Initial release of the MAC Control module.
//
//
//
//
//
`include "timescale.v"
module eth_receivecontrol (MTxClk, MRxClk, TxReset, RxReset, RxData, RxValid, RxStartFrm,
RxEndFrm, RxFlow, ReceiveEnd, MAC, DlyCrcEn, TxDoneIn,
TxAbortIn, TxStartFrmOut, ReceivedLengthOK, ReceivedPacketGood,
TxUsedDataOutDetected, Pause, ReceivedPauseFrm, AddressOK,
RxStatusWriteLatched_sync2, r_PassAll, SetPauseTimer
);
parameter Tp = 1;
input MTxClk;
input MRxClk;
input TxReset;
input RxReset;
input [7:0] RxData;
input RxValid;
input RxStartFrm;
input RxEndFrm;
input RxFlow;
input ReceiveEnd;
input [47:0]MAC;
input DlyCrcEn;
input TxDoneIn;
input TxAbortIn;
input TxStartFrmOut;
input ReceivedLengthOK;
input ReceivedPacketGood;
input TxUsedDataOutDetected;
input RxStatusWriteLatched_sync2;
input r_PassAll;
output Pause;
output ReceivedPauseFrm;
output AddressOK;
output SetPauseTimer;
reg Pause;
reg AddressOK; // Multicast or unicast address detected
reg TypeLengthOK; // Type/Length field contains 0x8808
reg DetectionWindow; // Detection of the PAUSE frame is possible within this window
reg OpCodeOK; // PAUSE opcode detected (0x0001)
reg [2:0] DlyCrcCnt;
reg [4:0] ByteCnt;
reg [15:0] AssembledTimerValue;
reg [15:0] LatchedTimerValue;
reg ReceivedPauseFrm;
reg ReceivedPauseFrmWAddr;
reg PauseTimerEq0_sync1;
reg PauseTimerEq0_sync2;
reg [15:0] PauseTimer;
reg Divider2;
reg [5:0] SlotTimer;
wire [47:0] ReservedMulticast; // 0x0180C2000001
wire [15:0] TypeLength; // 0x8808
wire ResetByteCnt; //
wire IncrementByteCnt; //
wire ByteCntEq0; // ByteCnt = 0
wire ByteCntEq1; // ByteCnt = 1
wire ByteCntEq2; // ByteCnt = 2
wire ByteCntEq3; // ByteCnt = 3
wire ByteCntEq4; // ByteCnt = 4
wire ByteCntEq5; // ByteCnt = 5
wire ByteCntEq12; // ByteCnt = 12
wire ByteCntEq13; // ByteCnt = 13
wire ByteCntEq14; // ByteCnt = 14
wire ByteCntEq15; // ByteCnt = 15
wire ByteCntEq16; // ByteCnt = 16
wire ByteCntEq17; // ByteCnt = 17
wire ByteCntEq18; // ByteCnt = 18
wire DecrementPauseTimer; //
wire PauseTimerEq0; //
wire ResetSlotTimer; //
wire IncrementSlotTimer; //
wire SlotFinished; //
// Reserved multicast address and Type/Length for PAUSE control
assign ReservedMulticast = 48'h0180C2000001;
assign TypeLength = 16'h8808;
// Address Detection (Multicast or unicast)
always @ (posedge MRxClk or posedge RxReset)
begin
if(RxReset)
AddressOK <= #Tp 1'b0;
else
if(DetectionWindow & ByteCntEq0)
AddressOK <= #Tp RxData[7:0] == ReservedMulticast[47:40] | RxData[7:0] == MAC[47:40];
else
if(DetectionWindow & ByteCntEq1)
AddressOK <= #Tp (RxData[7:0] == ReservedMulticast[39:32] | RxData[7:0] == MAC[39:32]) & AddressOK;
else
if(DetectionWindow & ByteCntEq2)
AddressOK <= #Tp (RxData[7:0] == ReservedMulticast[31:24] | RxData[7:0] == MAC[31:24]) & AddressOK;
else
if(DetectionWindow & ByteCntEq3)
AddressOK <= #Tp (RxData[7:0] == ReservedMulticast[23:16] | RxData[7:0] == MAC[23:16]) & AddressOK;
else
if(DetectionWindow & ByteCntEq4)
AddressOK <= #Tp (RxData[7:0] == ReservedMulticast[15:8] | RxData[7:0] == MAC[15:8]) & AddressOK;
else
if(DetectionWindow & ByteCntEq5)
AddressOK <= #Tp (RxData[7:0] == ReservedMulticast[7:0] | RxData[7:0] == MAC[7:0]) & AddressOK;
else
if(ReceiveEnd)
AddressOK <= #Tp 1'b0;
end
// TypeLengthOK (Type/Length Control frame detected)
always @ (posedge MRxClk or posedge RxReset )
begin
if(RxReset)
TypeLengthOK <= #Tp 1'b0;
else
if(DetectionWindow & ByteCntEq12)
TypeLengthOK <= #Tp ByteCntEq12 & (RxData[7:0] == TypeLength[15:8]);
else
if(DetectionWindow & ByteCntEq13)
TypeLengthOK <= #Tp ByteCntEq13 & (RxData[7:0] == TypeLength[7:0]) & TypeLengthOK;
else
if(ReceiveEnd)
TypeLengthOK <= #Tp 1'b0;
end
// Latch Control Frame Opcode
always @ (posedge MRxClk or posedge RxReset )
begin
if(RxReset)
OpCodeOK <= #Tp 1'b0;
else
if(ByteCntEq16)
OpCodeOK <= #Tp 1'b0;
else
begin
if(DetectionWindow & ByteCntEq14)
OpCodeOK <= #Tp ByteCntEq14 & RxData[7:0] == 8'h00;
if(DetectionWindow & ByteCntEq15)
OpCodeOK <= #Tp ByteCntEq15 & RxData[7:0] == 8'h01 & OpCodeOK;
end
end
// ReceivedPauseFrmWAddr (+Address Check)
always @ (posedge MRxClk or posedge RxReset )
begin
if(RxReset)
ReceivedPauseFrmWAddr <= #Tp 1'b0;
else
if(ReceiveEnd)
ReceivedPauseFrmWAddr <= #Tp 1'b0;
else
if(ByteCntEq16 & TypeLengthOK & OpCodeOK & AddressOK)
ReceivedPauseFrmWAddr <= #Tp 1'b1;
end
// Assembling 16-bit timer value from two 8-bit data
always @ (posedge MRxClk or posedge RxReset )
begin
if(RxReset)
AssembledTimerValue[15:0] <= #Tp 16'h0;
else
if(RxStartFrm)
AssembledTimerValue[15:0] <= #Tp 16'h0;
else
begin
if(DetectionWindow & ByteCntEq16)
AssembledTimerValue[15:8] <= #Tp RxData[7:0];
if(DetectionWindow & ByteCntEq17)
AssembledTimerValue[7:0] <= #Tp RxData[7:0];
end
end
// Detection window (while PAUSE detection is possible)
always @ (posedge MRxClk or posedge RxReset )
begin
if(RxReset)
DetectionWindow <= #Tp 1'b1;
else
if(ByteCntEq18)
DetectionWindow <= #Tp 1'b0;
else
if(ReceiveEnd)
DetectionWindow <= #Tp 1'b1;
end
// Latching Timer Value
always @ (posedge MRxClk or posedge RxReset )
begin
if(RxReset)
LatchedTimerValue[15:0] <= #Tp 16'h0;
else
if(DetectionWindow & ReceivedPauseFrmWAddr & ByteCntEq18)
LatchedTimerValue[15:0] <= #Tp AssembledTimerValue[15:0];
else
if(ReceiveEnd)
LatchedTimerValue[15:0] <= #Tp 16'h0;
end
// Delayed CEC counter
always @ (posedge MRxClk or posedge RxReset)
begin
if(RxReset)
DlyCrcCnt <= #Tp 3'h0;
else
if(RxValid & RxEndFrm)
DlyCrcCnt <= #Tp 3'h0;
else
if(RxValid & ~RxEndFrm & ~DlyCrcCnt[2])
DlyCrcCnt <= #Tp DlyCrcCnt + 1'b1;
end
assign ResetByteCnt = RxEndFrm;
assign IncrementByteCnt = RxValid & DetectionWindow & ~ByteCntEq18 & (~DlyCrcEn | DlyCrcEn & DlyCrcCnt[2]);
// Byte counter
always @ (posedge MRxClk or posedge RxReset)
begin
if(RxReset)
ByteCnt[4:0] <= #Tp 5'h0;
else
if(ResetByteCnt)
ByteCnt[4:0] <= #Tp 5'h0;
else
if(IncrementByteCnt)
ByteCnt[4:0] <= #Tp ByteCnt[4:0] + 1'b1;
end
assign ByteCntEq0 = RxValid & ByteCnt[4:0] == 5'h0;
assign ByteCntEq1 = RxValid & ByteCnt[4:0] == 5'h1;
assign ByteCntEq2 = RxValid & ByteCnt[4:0] == 5'h2;
assign ByteCntEq3 = RxValid & ByteCnt[4:0] == 5'h3;
assign ByteCntEq4 = RxValid & ByteCnt[4:0] == 5'h4;
assign ByteCntEq5 = RxValid & ByteCnt[4:0] == 5'h5;
assign ByteCntEq12 = RxValid & ByteCnt[4:0] == 5'h0C;
assign ByteCntEq13 = RxValid & ByteCnt[4:0] == 5'h0D;
assign ByteCntEq14 = RxValid & ByteCnt[4:0] == 5'h0E;
assign ByteCntEq15 = RxValid & ByteCnt[4:0] == 5'h0F;
assign ByteCntEq16 = RxValid & ByteCnt[4:0] == 5'h10;
assign ByteCntEq17 = RxValid & ByteCnt[4:0] == 5'h11;
assign ByteCntEq18 = RxValid & ByteCnt[4:0] == 5'h12 & DetectionWindow;
assign SetPauseTimer = ReceiveEnd & ReceivedPauseFrmWAddr & ReceivedPacketGood & ReceivedLengthOK & RxFlow;
assign DecrementPauseTimer = SlotFinished & |PauseTimer;
// PauseTimer[15:0]
always @ (posedge MRxClk or posedge RxReset)
begin
if(RxReset)
PauseTimer[15:0] <= #Tp 16'h0;
else
if(SetPauseTimer)
PauseTimer[15:0] <= #Tp LatchedTimerValue[15:0];
else
if(DecrementPauseTimer)
PauseTimer[15:0] <= #Tp PauseTimer[15:0] - 1'b1;
end
assign PauseTimerEq0 = ~(|PauseTimer[15:0]);
// Synchronization of the pause timer
always @ (posedge MTxClk or posedge TxReset)
begin
if(TxReset)
begin
PauseTimerEq0_sync1 <= #Tp 1'b1;
PauseTimerEq0_sync2 <= #Tp 1'b1;
end
else
begin
PauseTimerEq0_sync1 <= #Tp PauseTimerEq0;
PauseTimerEq0_sync2 <= #Tp PauseTimerEq0_sync1;
end
end
// Pause signal generation
always @ (posedge MTxClk or posedge TxReset)
begin
if(TxReset)
Pause <= #Tp 1'b0;
else
if((TxDoneIn | TxAbortIn | ~TxUsedDataOutDetected) & ~TxStartFrmOut)
Pause <= #Tp RxFlow & ~PauseTimerEq0_sync2;
end
// Divider2 is used for incrementing the Slot timer every other clock
always @ (posedge MRxClk or posedge RxReset)
begin
if(RxReset)
Divider2 <= #Tp 1'b0;
else
if(|PauseTimer[15:0] & RxFlow)
Divider2 <= #Tp ~Divider2;
else
Divider2 <= #Tp 1'b0;
end
assign ResetSlotTimer = RxReset;
assign IncrementSlotTimer = Pause & RxFlow & Divider2;
// SlotTimer
always @ (posedge MRxClk or posedge RxReset)
begin
if(RxReset)
SlotTimer[5:0] <= #Tp 6'h0;
else
if(ResetSlotTimer)
SlotTimer[5:0] <= #Tp 6'h0;
else
if(IncrementSlotTimer)
SlotTimer[5:0] <= #Tp SlotTimer[5:0] + 1'b1;
end
assign SlotFinished = &SlotTimer[5:0] & IncrementSlotTimer; // Slot is 512 bits (64 bytes)
// Pause Frame received
always @ (posedge MRxClk or posedge RxReset)
begin
if(RxReset)
ReceivedPauseFrm <=#Tp 1'b0;
else
if(RxStatusWriteLatched_sync2 & r_PassAll | ReceivedPauseFrm & (~r_PassAll))
ReceivedPauseFrm <=#Tp 1'b0;
else
if(ByteCntEq16 & TypeLengthOK & OpCodeOK)
ReceivedPauseFrm <=#Tp 1'b1;
end
endmodule