该文件包含以太网IP核的相关代码
源代码在线查看： eth_receivecontrol.v
//////////////////////////////////////////////////////////////////////
//// ////
//// eth_receivecontrol.v ////
//// ////
//// This file is part of the Ethernet IP core project ////
//// http://www.opencores.org/cores/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 1.2 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, PassAll, DlyCrcEn, TxDoneIn,
TxAbortIn, TxStartFrmOut, ReceivedLengthOK, ReceivedPacketGood,
TxUsedDataOutDetected, Pause, ReceivedPauseFrm
);
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 PassAll;
input DlyCrcEn;
input TxDoneIn;
input TxAbortIn;
input TxStartFrmOut;
input ReceivedLengthOK;
input ReceivedPacketGood;
input TxUsedDataOutDetected;
output Pause;
output ReceivedPauseFrm;
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 SetPauseTimer; //
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 else
if(DetectionWindow & ByteCntEq0)
AddressOK else
if(DetectionWindow & ByteCntEq1)
AddressOK else
if(DetectionWindow & ByteCntEq2)
AddressOK else
if(DetectionWindow & ByteCntEq3)
AddressOK else
if(DetectionWindow & ByteCntEq4)
AddressOK else
if(DetectionWindow & ByteCntEq5)
AddressOK else
if(ReceiveEnd)
AddressOK end
// TypeLengthOK (Type/Length Control frame detected)
always @ (posedge MRxClk or posedge RxReset )
begin
if(RxReset)
TypeLengthOK else
if(DetectionWindow & ByteCntEq12)
TypeLengthOK else
if(DetectionWindow & ByteCntEq13)
TypeLengthOK else
if(ReceiveEnd)
TypeLengthOK end
// Latch Control Frame Opcode
always @ (posedge MRxClk or posedge RxReset )
begin
if(RxReset)
OpCodeOK else
if(RxStartFrm)
OpCodeOK else
begin
if(DetectionWindow & ByteCntEq14)
OpCodeOK
if(DetectionWindow & ByteCntEq15)
OpCodeOK end
end
// ReceivedPauseFrmWAddr (+Address Check)
always @ (posedge MRxClk or posedge RxReset )
begin
if(RxReset)
ReceivedPauseFrmWAddr else
if(ReceiveEnd)
ReceivedPauseFrmWAddr else
if(ByteCntEq16 & TypeLengthOK & OpCodeOK & AddressOK)
ReceivedPauseFrmWAddr end
// Assembling 16-bit timer value from two 8-bit data
always @ (posedge MRxClk or posedge RxReset )
begin
if(RxReset)
AssembledTimerValue[15:0] else
if(RxStartFrm)
AssembledTimerValue[15:0] else
begin
if(DetectionWindow & ByteCntEq16)
AssembledTimerValue[15:8] if(DetectionWindow & ByteCntEq17)
AssembledTimerValue[7:0] end
end
// Detection window (while PAUSE detection is possible)
always @ (posedge MRxClk or posedge RxReset )
begin
if(RxReset)
DetectionWindow else
if(ByteCntEq18)
DetectionWindow else
if(ReceiveEnd)
DetectionWindow end
// Latching Timer Value
always @ (posedge MRxClk or posedge RxReset )
begin
if(RxReset)
LatchedTimerValue[15:0] else
if(~PassAll & DetectionWindow & ReceivedPauseFrmWAddr & ByteCntEq18)
LatchedTimerValue[15:0] else
if(ReceiveEnd)
LatchedTimerValue[15:0] end
// Delayed CEC counter
always @ (posedge MRxClk or posedge RxReset)
begin
if(RxReset)
DlyCrcCnt else
if(RxValid & RxEndFrm)
DlyCrcCnt else
if(RxValid & ~RxEndFrm & ~DlyCrcCnt[2])
DlyCrcCnt 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] else
if(ResetByteCnt)
ByteCnt[4:0] else
if(IncrementByteCnt)
ByteCnt[4:0] 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] else
if(SetPauseTimer)
PauseTimer[15:0] else
if(DecrementPauseTimer)
PauseTimer[15:0] end
assign PauseTimerEq0 = ~(|PauseTimer[15:0]);
// Synchronization of the pause timer
always @ (posedge MTxClk or posedge TxReset)
begin
if(TxReset)
begin
PauseTimerEq0_sync1 PauseTimerEq0_sync2 end
else
begin
PauseTimerEq0_sync1 PauseTimerEq0_sync2 end
end
// Pause signal generation
always @ (posedge MTxClk or posedge TxReset)
begin
if(TxReset)
Pause else
if((TxDoneIn | TxAbortIn | ~TxUsedDataOutDetected) & ~TxStartFrmOut)
Pause end
// Divider2 is used for incrementing the Slot timer every other clock
always @ (posedge MRxClk or posedge RxReset)
begin
if(RxReset)
Divider2 else
if(|PauseTimer[15:0] & RxFlow)
Divider2 else
Divider2 end
assign ResetSlotTimer = RxReset;
assign IncrementSlotTimer = Pause & RxFlow & Divider2;
// SlotTimer
always @ (posedge MRxClk or posedge RxReset)
begin
if(RxReset)
SlotTimer[5:0] else
if(ResetSlotTimer)
SlotTimer[5:0] else
if(IncrementSlotTimer)
SlotTimer[5:0] 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 else
if(ByteCntEq16 & TypeLengthOK & OpCodeOK)
ReceivedPauseFrm else
if(ReceiveEnd)
ReceivedPauseFrm end
endmodule
