此文档为采用FPGA实现的以太网MAC层
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/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 1.1 2005/10/05 01:34:00 jdhar // initial checkin with TSK3000 processor // // Revision 1.1 2005/07/31 05:51:11 jdhar // initial commit for TSK3000 files // // 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 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(ByteCntEq16) 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(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(RxStatusWriteLatched_sync2 & r_PassAll | ReceivedPauseFrm & (~r_PassAll)) ReceivedPauseFrm else if(ByteCntEq16 & TypeLengthOK & OpCodeOK) ReceivedPauseFrm end endmodule