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

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//////////////////////////////////////////////////////////////////////
//// ////
//// eth_wishbone.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 available in the Readme.txt ////
//// file. ////
//// ////
//////////////////////////////////////////////////////////////////////
//// ////
//// Copyright (C) 2001, 2002 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_wishbone.v,v $
// Revision 1.58 2005/03/21 20:07:18 igorm
// Some small fixes + some troubles fixed.
//
// Revision 1.57 2005/02/21 11:35:33 igorm
// Defer indication fixed.
//
// Revision 1.56 2004/04/30 10:30:00 igorm
// Accidently deleted line put back.
//
// Revision 1.55 2004/04/26 15:26:23 igorm
// - Bug connected to the TX_BD_NUM_Wr signal fixed (bug came in with the
// previous update of the core.
// - TxBDAddress is set to 0 after the TX is enabled in the MODER register.
// - RxBDAddress is set to r_TxBDNum<<1 after the RX is enabled in the MODER
// register. (thanks to Mathias and Torbjorn)
// - Multicast reception was fixed. Thanks to Ulrich Gries
//
// Revision 1.54 2003/11/12 18:24:59 tadejm
// WISHBONE slave changed and tested from only 32-bit accesss to byte access.
//
// Revision 1.53 2003/10/17 07:46:17 markom
// mbist signals updated according to newest convention
//
// Revision 1.52 2003/01/30 14:51:31 mohor
// Reset has priority in some flipflops.
//
// Revision 1.51 2003/01/30 13:36:22 mohor
// A new bug (entered with previous update) fixed. When abort occured sometimes
// data transmission was blocked.
//
// Revision 1.50 2003/01/22 13:49:26 tadejm
// When control packets were received, they were ignored in some cases.
//
// Revision 1.49 2003/01/21 12:09:40 mohor
// When receiving normal data frame and RxFlow control was switched on, RXB
// interrupt was not set.
//
// Revision 1.48 2003/01/20 12:05:26 mohor
// When in full duplex, transmit was sometimes blocked. Fixed.
//
// Revision 1.47 2002/11/22 13:26:21 mohor
// Registers RxStatusWrite_rck and RxStatusWriteLatched were not used
// anywhere. Removed.
//
// Revision 1.46 2002/11/22 01:57:06 mohor
// Rx Flow control fixed. CF flag added to the RX buffer descriptor. RxAbort
// synchronized.
//
// Revision 1.45 2002/11/19 17:33:34 mohor
// AddressMiss status is connecting to the Rx BD. AddressMiss is identifying
// that a frame was received because of the promiscous mode.
//
// Revision 1.44 2002/11/13 22:21:40 tadejm
// RxError is not generated when small frame reception is enabled and small
// frames are received.
//
// Revision 1.43 2002/10/18 20:53:34 mohor
// case changed to casex.
//
// Revision 1.42 2002/10/18 17:04:20 tadejm
// Changed BIST scan signals.
//
// Revision 1.41 2002/10/18 15:42:09 tadejm
// Igor added WB burst support and repaired BUG when handling TX under-run and retry.
//
// Revision 1.40 2002/10/14 16:07:02 mohor
// TxStatus is written after last access to the TX fifo is finished (in case of abort
// or retry). TxDone is fixed.
//
// Revision 1.39 2002/10/11 15:35:20 mohor
// txfifo_cnt and rxfifo_cnt counters width is defined in the eth_define.v file,
// TxDone and TxRetry are generated after the current WISHBONE access is
// finished.
//
// Revision 1.38 2002/10/10 16:29:30 mohor
// BIST added.
//
// Revision 1.37 2002/09/11 14:18:46 mohor
// Sometimes both RxB_IRQ and RxE_IRQ were activated. Bug fixed.
//
// Revision 1.36 2002/09/10 13:48:46 mohor
// Reception is possible after RxPointer is read and not after BD is read. For
// that reason RxBDReady is changed to RxReady.
// Busy_IRQ interrupt connected. When there is no RxBD ready and frame
// comes, interrupt is generated.
//
// Revision 1.35 2002/09/10 10:35:23 mohor
// Ethernet debug registers removed.
//
// Revision 1.34 2002/09/08 16:31:49 mohor
// Async reset for WB_ACK_O removed (when core was in reset, it was
// impossible to access BDs).
// RxPointers and TxPointers names changed to be more descriptive.
// TxUnderRun synchronized.
//
// Revision 1.33 2002/09/04 18:47:57 mohor
// Debug registers reg1, 2, 3, 4 connected. Synchronization of many signals
// changed (bugs fixed). Access to un-alligned buffers fixed. RxAbort signal
// was not used OK.
//
// Revision 1.32 2002/08/14 19:31:48 mohor
// Register TX_BD_NUM is changed so it contains value of the Tx buffer descriptors. No
// need to multiply or devide any more.
//
// Revision 1.31 2002/07/25 18:29:01 mohor
// WriteRxDataToMemory signal changed so end of frame (when last word is
// written to fifo) is changed.
//
// Revision 1.30 2002/07/23 15:28:31 mohor
// Ram , used for BDs changed from generic_spram to eth_spram_256x32.
//
// Revision 1.29 2002/07/20 00:41:32 mohor
// ShiftEnded synchronization changed.
//
// Revision 1.28 2002/07/18 16:11:46 mohor
// RxBDAddress takes `ETH_TX_BD_NUM_DEF value after reset.
//
// Revision 1.27 2002/07/11 02:53:20 mohor
// RxPointer bug fixed.
//
// Revision 1.26 2002/07/10 13:12:38 mohor
// Previous bug wasn't succesfully removed. Now fixed.
//
// Revision 1.25 2002/07/09 23:53:24 mohor
// Master state machine had a bug when switching from master write to
// master read.
//
// Revision 1.24 2002/07/09 20:44:41 mohor
// m_wb_cyc_o signal released after every single transfer.
//
// Revision 1.23 2002/05/03 10:15:50 mohor
// Outputs registered. Reset changed for eth_wishbone module.
//
// Revision 1.22 2002/04/24 08:52:19 mohor
// Compiler directives added. Tx and Rx fifo size incremented. A "late collision"
// bug fixed.
//
// Revision 1.21 2002/03/29 16:18:11 lampret
// Small typo fixed.
//
// Revision 1.20 2002/03/25 16:19:12 mohor
// Any address can be used for Tx and Rx BD pointers. Address does not need
// to be aligned.
//
// Revision 1.19 2002/03/19 12:51:50 mohor
// Comments in Slovene language removed.
//
// Revision 1.18 2002/03/19 12:46:52 mohor
// casex changed with case, fifo reset changed.
//
// Revision 1.17 2002/03/09 16:08:45 mohor
// rx_fifo was not always cleared ok. Fixed.
//
// Revision 1.16 2002/03/09 13:51:20 mohor
// Status was not latched correctly sometimes. Fixed.
//
// Revision 1.15 2002/03/08 06:56:46 mohor
// Big Endian problem when sending frames fixed.
//
// Revision 1.14 2002/03/02 19:12:40 mohor
// Byte ordering changed (Big Endian used). casex changed with case because
// Xilinx Foundation had problems. Tested in HW. It WORKS.
//
// Revision 1.13 2002/02/26 16:59:55 mohor
// Small fixes for external/internal DMA missmatches.
//
// Revision 1.12 2002/02/26 16:22:07 mohor
// Interrupts changed
//
// Revision 1.11 2002/02/15 17:07:39 mohor
// Status was not written correctly when frames were discarted because of
// address mismatch.
//
// Revision 1.10 2002/02/15 12:17:39 mohor
// RxStartFrm cleared when abort or retry comes.
//
// Revision 1.9 2002/02/15 11:59:10 mohor
// Changes that were lost when updating from 1.5 to 1.8 fixed.
//
// Revision 1.8 2002/02/14 20:54:33 billditt
// Addition of new module eth_addrcheck.v
//
// Revision 1.7 2002/02/12 17:03:47 mohor
// RxOverRun added to statuses.
//
// Revision 1.6 2002/02/11 09:18:22 mohor
// Tx status is written back to the BD.
//
// Revision 1.5 2002/02/08 16:21:54 mohor
// Rx status is written back to the BD.
//
// Revision 1.4 2002/02/06 14:10:21 mohor
// non-DMA host interface added. Select the right configutation in eth_defines.
//
// Revision 1.3 2002/02/05 16:44:39 mohor
// Both rx and tx part are finished. Tested with wb_clk_i between 10 and 200
// MHz. Statuses, overrun, control frame transmission and reception still need
// to be fixed.
//
// Revision 1.2 2002/02/01 12:46:51 mohor
// Tx part finished. TxStatus needs to be fixed. Pause request needs to be
// added.
//
// Revision 1.1 2002/01/23 10:47:59 mohor
// Initial version. Equals to eth_wishbonedma.v at this moment.
//
//
//
`include "eth_defines.v"
`include "timescale.v"
module eth_wishbone
(
// WISHBONE common
WB_CLK_I, WB_DAT_I, WB_DAT_O,
// WISHBONE slave
WB_ADR_I, WB_WE_I, WB_ACK_O,
BDCs,
Reset,
// WISHBONE master
m_wb_adr_o, m_wb_sel_o, m_wb_we_o,
m_wb_dat_o, m_wb_dat_i, m_wb_cyc_o,
m_wb_stb_o, m_wb_ack_i, m_wb_err_i,
`ifdef ETH_WISHBONE_B3
m_wb_cti_o, m_wb_bte_o,
`endif
//TX
MTxClk, TxStartFrm, TxEndFrm, TxUsedData, TxData,
TxRetry, TxAbort, TxUnderRun, TxDone, PerPacketCrcEn,
PerPacketPad,
//RX
MRxClk, RxData, RxValid, RxStartFrm, RxEndFrm, RxAbort, RxStatusWriteLatched_sync2,
// Register
r_TxEn, r_RxEn, r_TxBDNum, r_RxFlow, r_PassAll,
// Interrupts
TxB_IRQ, TxE_IRQ, RxB_IRQ, RxE_IRQ, Busy_IRQ,
// Rx Status
InvalidSymbol, LatchedCrcError, RxLateCollision, ShortFrame, DribbleNibble,
ReceivedPacketTooBig, RxLength, LoadRxStatus, ReceivedPacketGood, AddressMiss,
ReceivedPauseFrm,
// Tx Status
RetryCntLatched, RetryLimit, LateCollLatched, DeferLatched, RstDeferLatched, CarrierSenseLost
// Bist
`ifdef ETH_BIST
,
// debug chain signals
mbist_si_i, // bist scan serial in
mbist_so_o, // bist scan serial out
mbist_ctrl_i // bist chain shift control
`endif
);
parameter Tp = 1;
// WISHBONE common
input WB_CLK_I; // WISHBONE clock
input [31:0] WB_DAT_I; // WISHBONE data input
output [31:0] WB_DAT_O; // WISHBONE data output
// WISHBONE slave
input [9:2] WB_ADR_I; // WISHBONE address input
input WB_WE_I; // WISHBONE write enable input
input [3:0] BDCs; // Buffer descriptors are selected
output WB_ACK_O; // WISHBONE acknowledge output
// WISHBONE master
output [29:0] m_wb_adr_o; //
output [3:0] m_wb_sel_o; //
output m_wb_we_o; //
output [31:0] m_wb_dat_o; //
output m_wb_cyc_o; //
output m_wb_stb_o; //
input [31:0] m_wb_dat_i; //
input m_wb_ack_i; //
input m_wb_err_i; //
`ifdef ETH_WISHBONE_B3
output [2:0] m_wb_cti_o; // Cycle Type Identifier
output [1:0] m_wb_bte_o; // Burst Type Extension
reg [2:0] m_wb_cti_o; // Cycle Type Identifier
`endif
input Reset; // Reset signal
// Rx Status signals
input InvalidSymbol; // Invalid symbol was received during reception in 100 Mbps mode
input LatchedCrcError; // CRC error
input RxLateCollision; // Late collision occured while receiving frame
input ShortFrame; // Frame shorter then the minimum size (r_MinFL) was received while small packets are enabled (r_RecSmall)
input DribbleNibble; // Extra nibble received
input ReceivedPacketTooBig;// Received packet is bigger than r_MaxFL
input [15:0] RxLength; // Length of the incoming frame
input LoadRxStatus; // Rx status was loaded
input ReceivedPacketGood;// Received packet's length and CRC are good
input AddressMiss; // When a packet is received AddressMiss status is written to the Rx BD
input r_RxFlow;
input r_PassAll;
input ReceivedPauseFrm;
// Tx Status signals
input [3:0] RetryCntLatched; // Latched Retry Counter
input RetryLimit; // Retry limit reached (Retry Max value + 1 attempts were made)
input LateCollLatched; // Late collision occured
input DeferLatched; // Defer indication (Frame was defered before sucessfully sent)
output RstDeferLatched;
input CarrierSenseLost; // Carrier Sense was lost during the frame transmission
// Tx
input MTxClk; // Transmit clock (from PHY)
input TxUsedData; // Transmit packet used data
input TxRetry; // Transmit packet retry
input TxAbort; // Transmit packet abort
input TxDone; // Transmission ended
output TxStartFrm; // Transmit packet start frame
output TxEndFrm; // Transmit packet end frame
output [7:0] TxData; // Transmit packet data byte
output TxUnderRun; // Transmit packet under-run
output PerPacketCrcEn; // Per packet crc enable
output PerPacketPad; // Per packet pading
// Rx
input MRxClk; // Receive clock (from PHY)
input [7:0] RxData; // Received data byte (from PHY)
input RxValid; //
input RxStartFrm; //
input RxEndFrm; //
input RxAbort; // This signal is set when address doesn't match.
output RxStatusWriteLatched_sync2;
//Register
input r_TxEn; // Transmit enable
input r_RxEn; // Receive enable
input [7:0] r_TxBDNum; // Receive buffer descriptor number
// Interrupts
output TxB_IRQ;
output TxE_IRQ;
output RxB_IRQ;
output RxE_IRQ;
output Busy_IRQ;
// Bist
`ifdef ETH_BIST
input mbist_si_i; // bist scan serial in
output mbist_so_o; // bist scan serial out
input [`ETH_MBIST_CTRL_WIDTH - 1:0] mbist_ctrl_i; // bist chain shift control
`endif
reg TxB_IRQ;
reg TxE_IRQ;
reg RxB_IRQ;
reg RxE_IRQ;
reg TxStartFrm;
reg TxEndFrm;
reg [7:0] TxData;
reg TxUnderRun;
reg TxUnderRun_wb;
reg TxBDRead;
wire TxStatusWrite;
reg [1:0] TxValidBytesLatched;
reg [15:0] TxLength;
reg [15:0] LatchedTxLength;
reg [14:11] TxStatus;
reg [14:13] RxStatus;
reg TxStartFrm_wb;
reg TxRetry_wb;
reg TxAbort_wb;
reg TxDone_wb;
reg TxDone_wb_q;
reg TxAbort_wb_q;
reg TxRetry_wb_q;
reg TxRetryPacket;
reg TxRetryPacket_NotCleared;
reg TxDonePacket;
reg TxDonePacket_NotCleared;
reg TxAbortPacket;
reg TxAbortPacket_NotCleared;
reg RxBDReady;
reg RxReady;
reg TxBDReady;
reg RxBDRead;
reg [31:0] TxDataLatched;
reg [1:0] TxByteCnt;
reg LastWord;
reg ReadTxDataFromFifo_tck;
reg BlockingTxStatusWrite;
reg BlockingTxBDRead;
reg Flop;
reg [7:1] TxBDAddress;
reg [7:1] RxBDAddress;
reg TxRetrySync1;
reg TxAbortSync1;
reg TxDoneSync1;
reg TxAbort_q;
reg TxRetry_q;
reg TxUsedData_q;
reg [31:0] RxDataLatched2;
reg [31:8] RxDataLatched1; // Big Endian Byte Ordering
reg [1:0] RxValidBytes;
reg [1:0] RxByteCnt;
reg LastByteIn;
reg ShiftWillEnd;
reg WriteRxDataToFifo;
reg [15:0] LatchedRxLength;
reg RxAbortLatched;
reg ShiftEnded;
reg RxOverrun;
reg [3:0] BDWrite; // BD Write Enable for access from WISHBONE side
reg BDRead; // BD Read access from WISHBONE side
wire [31:0] RxBDDataIn; // Rx BD data in
wire [31:0] TxBDDataIn; // Tx BD data in
reg TxEndFrm_wb;
wire TxRetryPulse;
wire TxDonePulse;
wire TxAbortPulse;
wire StartRxBDRead;
wire StartTxBDRead;
wire TxIRQEn;
wire WrapTxStatusBit;
wire RxIRQEn;
wire WrapRxStatusBit;
wire [1:0] TxValidBytes;
wire [7:1] TempTxBDAddress;
wire [7:1] TempRxBDAddress;
wire RxStatusWrite;
wire RxBufferFull;
wire RxBufferAlmostEmpty;
wire RxBufferEmpty;
reg WB_ACK_O;
wire [8:0] RxStatusIn;
reg [8:0] RxStatusInLatched;
reg WbEn, WbEn_q;
reg RxEn, RxEn_q;
reg TxEn, TxEn_q;
reg r_TxEn_q;
reg r_RxEn_q;
wire ram_ce;
wire [3:0] ram_we;
wire ram_oe;
reg [7:0] ram_addr;
reg [31:0] ram_di;
wire [31:0] ram_do;
wire StartTxPointerRead;
reg TxPointerRead;
reg TxEn_needed;
reg RxEn_needed;
wire StartRxPointerRead;
reg RxPointerRead;
`ifdef ETH_WISHBONE_B3
assign m_wb_bte_o = 2'b00; // Linear burst
`endif
assign m_wb_stb_o = m_wb_cyc_o;
always @ (posedge WB_CLK_I)
begin
WB_ACK_O <=#Tp (|BDWrite) & WbEn & WbEn_q | BDRead & WbEn & ~WbEn_q;
end
assign WB_DAT_O = ram_do;
// Generic synchronous single-port RAM interface
eth_spram_256x32 bd_ram (
.clk(WB_CLK_I), .rst(Reset), .ce(ram_ce), .we(ram_we), .oe(ram_oe), .addr(ram_addr), .di(ram_di), .do(ram_do)
`ifdef ETH_BIST
,
.mbist_si_i (mbist_si_i),
.mbist_so_o (mbist_so_o),
.mbist_ctrl_i (mbist_ctrl_i)
`endif
);
assign ram_ce = 1'b1;
assign ram_we = (BDWrite & {4{(WbEn & WbEn_q)}}) | {4{(TxStatusWrite | RxStatusWrite)}};
assign ram_oe = BDRead & WbEn & WbEn_q | TxEn & TxEn_q & (TxBDRead | TxPointerRead) | RxEn & RxEn_q & (RxBDRead | RxPointerRead);
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxEn_needed <=#Tp 1'b0;
else
if(~TxBDReady & r_TxEn & WbEn & ~WbEn_q)
TxEn_needed <=#Tp 1'b1;
else
if(TxPointerRead & TxEn & TxEn_q)
TxEn_needed <=#Tp 1'b0;
end
// Enabling access to the RAM for three devices.
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
begin
WbEn <=#Tp 1'b1;
RxEn <=#Tp 1'b0;
TxEn <=#Tp 1'b0;
ram_addr <=#Tp 8'h0;
ram_di <=#Tp 32'h0;
BDRead <=#Tp 1'b0;
BDWrite <=#Tp 1'b0;
end
else
begin
// Switching between three stages depends on enable signals
case ({WbEn_q, RxEn_q, TxEn_q, RxEn_needed, TxEn_needed}) // synopsys parallel_case
5'b100_10, 5'b100_11 :
begin
WbEn <=#Tp 1'b0;
RxEn <=#Tp 1'b1; // wb access stage and r_RxEn is enabled
TxEn <=#Tp 1'b0;
ram_addr <=#Tp {RxBDAddress, RxPointerRead};
ram_di <=#Tp RxBDDataIn;
end
5'b100_01 :
begin
WbEn <=#Tp 1'b0;
RxEn <=#Tp 1'b0;
TxEn <=#Tp 1'b1; // wb access stage, r_RxEn is disabled but r_TxEn is enabled
ram_addr <=#Tp {TxBDAddress, TxPointerRead};
ram_di <=#Tp TxBDDataIn;
end
5'b010_00, 5'b010_10 :
begin
WbEn <=#Tp 1'b1; // RxEn access stage and r_TxEn is disabled
RxEn <=#Tp 1'b0;
TxEn <=#Tp 1'b0;
ram_addr <=#Tp WB_ADR_I[9:2];
ram_di <=#Tp WB_DAT_I;
BDWrite <=#Tp BDCs[3:0] & {4{WB_WE_I}};
BDRead <=#Tp (|BDCs) & ~WB_WE_I;
end
5'b010_01, 5'b010_11 :
begin
WbEn <=#Tp 1'b0;
RxEn <=#Tp 1'b0;
TxEn <=#Tp 1'b1; // RxEn access stage and r_TxEn is enabled
ram_addr <=#Tp {TxBDAddress, TxPointerRead};
ram_di <=#Tp TxBDDataIn;
end
5'b001_00, 5'b001_01, 5'b001_10, 5'b001_11 :
begin
WbEn <=#Tp 1'b1; // TxEn access stage (we always go to wb access stage)
RxEn <=#Tp 1'b0;
TxEn <=#Tp 1'b0;
ram_addr <=#Tp WB_ADR_I[9:2];
ram_di <=#Tp WB_DAT_I;
BDWrite <=#Tp BDCs[3:0] & {4{WB_WE_I}};
BDRead <=#Tp (|BDCs) & ~WB_WE_I;
end
5'b100_00 :
begin
WbEn <=#Tp 1'b0; // WbEn access stage and there is no need for other stages. WbEn needs to be switched off for a bit
end
5'b000_00 :
begin
WbEn <=#Tp 1'b1; // Idle state. We go to WbEn access stage.
RxEn <=#Tp 1'b0;
TxEn <=#Tp 1'b0;
ram_addr <=#Tp WB_ADR_I[9:2];
ram_di <=#Tp WB_DAT_I;
BDWrite <=#Tp BDCs[3:0] & {4{WB_WE_I}};
BDRead <=#Tp (|BDCs) & ~WB_WE_I;
end
endcase
end
end
// Delayed stage signals
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
begin
WbEn_q <=#Tp 1'b0;
RxEn_q <=#Tp 1'b0;
TxEn_q <=#Tp 1'b0;
r_TxEn_q <=#Tp 1'b0;
r_RxEn_q <=#Tp 1'b0;
end
else
begin
WbEn_q <=#Tp WbEn;
RxEn_q <=#Tp RxEn;
TxEn_q <=#Tp TxEn;
r_TxEn_q <=#Tp r_TxEn;
r_RxEn_q <=#Tp r_RxEn;
end
end
// Changes for tx occur every second clock. Flop is used for this manner.
always @ (posedge MTxClk or posedge Reset)
begin
if(Reset)
Flop <=#Tp 1'b0;
else
if(TxDone | TxAbort | TxRetry_q)
Flop <=#Tp 1'b0;
else
if(TxUsedData)
Flop <=#Tp ~Flop;
end
wire ResetTxBDReady;
assign ResetTxBDReady = TxDonePulse | TxAbortPulse | TxRetryPulse;
// Latching READY status of the Tx buffer descriptor
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxBDReady <=#Tp 1'b0;
else
if(TxEn & TxEn_q & TxBDRead)
TxBDReady <=#Tp ram_do[15] & (ram_do[31:16] > 4); // TxBDReady is sampled only once at the beginning.
else // Only packets larger then 4 bytes are transmitted.
if(ResetTxBDReady)
TxBDReady <=#Tp 1'b0;
end
// Reading the Tx buffer descriptor
assign StartTxBDRead = (TxRetryPacket_NotCleared | TxStatusWrite) & ~BlockingTxBDRead & ~TxBDReady;
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxBDRead <=#Tp 1'b1;
else
if(StartTxBDRead)
TxBDRead <=#Tp 1'b1;
else
if(TxBDReady)
TxBDRead <=#Tp 1'b0;
end
// Reading Tx BD pointer
assign StartTxPointerRead = TxBDRead & TxBDReady;
// Reading Tx BD Pointer
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxPointerRead <=#Tp 1'b0;
else
if(StartTxPointerRead)
TxPointerRead <=#Tp 1'b1;
else
if(TxEn_q)
TxPointerRead <=#Tp 1'b0;
end
// Writing status back to the Tx buffer descriptor
assign TxStatusWrite = (TxDonePacket_NotCleared | TxAbortPacket_NotCleared) & TxEn & TxEn_q & ~BlockingTxStatusWrite;
// Status writing must occur only once. Meanwhile it is blocked.
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
BlockingTxStatusWrite <=#Tp 1'b0;
else
if(~TxDone_wb & ~TxAbort_wb)
BlockingTxStatusWrite <=#Tp 1'b0;
else
if(TxStatusWrite)
BlockingTxStatusWrite <=#Tp 1'b1;
end
reg BlockingTxStatusWrite_sync1;
reg BlockingTxStatusWrite_sync2;
reg BlockingTxStatusWrite_sync3;
// Synchronizing BlockingTxStatusWrite to MTxClk
always @ (posedge MTxClk or posedge Reset)
begin
if(Reset)
BlockingTxStatusWrite_sync1 <=#Tp 1'b0;
else
BlockingTxStatusWrite_sync1 <=#Tp BlockingTxStatusWrite;
end
// Synchronizing BlockingTxStatusWrite to MTxClk
always @ (posedge MTxClk or posedge Reset)
begin
if(Reset)
BlockingTxStatusWrite_sync2 <=#Tp 1'b0;
else
BlockingTxStatusWrite_sync2 <=#Tp BlockingTxStatusWrite_sync1;
end
// Synchronizing BlockingTxStatusWrite to MTxClk
always @ (posedge MTxClk or posedge Reset)
begin
if(Reset)
BlockingTxStatusWrite_sync3 <=#Tp 1'b0;
else
BlockingTxStatusWrite_sync3 <=#Tp BlockingTxStatusWrite_sync2;
end
assign RstDeferLatched = BlockingTxStatusWrite_sync2 & ~BlockingTxStatusWrite_sync3;
// TxBDRead state is activated only once.
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
BlockingTxBDRead <=#Tp 1'b0;
else
if(StartTxBDRead)
BlockingTxBDRead <=#Tp 1'b1;
else
if(~StartTxBDRead & ~TxBDReady)
BlockingTxBDRead <=#Tp 1'b0;
end
// Latching status from the tx buffer descriptor
// Data is avaliable one cycle after the access is started (at that time signal TxEn is not active)
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxStatus <=#Tp 4'h0;
else
if(TxEn & TxEn_q & TxBDRead)
TxStatus <=#Tp ram_do[14:11];
end
reg ReadTxDataFromMemory;
wire WriteRxDataToMemory;
reg MasterWbTX;
reg MasterWbRX;
reg [29:0] m_wb_adr_o;
reg m_wb_cyc_o;
reg [3:0] m_wb_sel_o;
reg m_wb_we_o;
wire TxLengthEq0;
wire TxLengthLt4;
reg BlockingIncrementTxPointer;
reg [31:2] TxPointerMSB;
reg [1:0] TxPointerLSB;
reg [1:0] TxPointerLSB_rst;
reg [31:2] RxPointerMSB;
reg [1:0] RxPointerLSB_rst;
wire RxBurstAcc;
wire RxWordAcc;
wire RxHalfAcc;
wire RxByteAcc;
//Latching length from the buffer descriptor;
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxLength <=#Tp 16'h0;
else
if(TxEn & TxEn_q & TxBDRead)
TxLength <=#Tp ram_do[31:16];
else
if(MasterWbTX & m_wb_ack_i)
begin
if(TxLengthLt4)
TxLength <=#Tp 16'h0;
else
if(TxPointerLSB_rst==2'h0)
TxLength <=#Tp TxLength - 3'h4; // Length is subtracted at the data request
else
if(TxPointerLSB_rst==2'h1)
TxLength <=#Tp TxLength - 3'h3; // Length is subtracted at the data request
else
if(TxPointerLSB_rst==2'h2)
TxLength <=#Tp TxLength - 3'h2; // Length is subtracted at the data request
else
if(TxPointerLSB_rst==2'h3)
TxLength <=#Tp TxLength - 3'h1; // Length is subtracted at the data request
end
end
//Latching length from the buffer descriptor;
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
LatchedTxLength <=#Tp 16'h0;
else
if(TxEn & TxEn_q & TxBDRead)
LatchedTxLength <=#Tp ram_do[31:16];
end
assign TxLengthEq0 = TxLength == 0;
assign TxLengthLt4 = TxLength < 4;
reg cyc_cleared;
reg IncrTxPointer;
// Latching Tx buffer pointer from buffer descriptor. Only 30 MSB bits are latched
// because TxPointerMSB is only used for word-aligned accesses.
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxPointerMSB <=#Tp 30'h0;
else
if(TxEn & TxEn_q & TxPointerRead)
TxPointerMSB <=#Tp ram_do[31:2];
else
if(IncrTxPointer & ~BlockingIncrementTxPointer)
TxPointerMSB <=#Tp TxPointerMSB + 1'b1; // TxPointer is word-aligned
end
// Latching 2 MSB bits of the buffer descriptor. Since word accesses are performed,
// valid data does not necesserly start at byte 0 (could be byte 0, 1, 2 or 3). This
// signals are used for proper selection of the start byte (TxData and TxByteCnt) are
// set by this two bits.
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxPointerLSB[1:0] <=#Tp 0;
else
if(TxEn & TxEn_q & TxPointerRead)
TxPointerLSB[1:0] <=#Tp ram_do[1:0];
end
// Latching 2 MSB bits of the buffer descriptor.
// After the read access, TxLength needs to be decremented for the number of the valid
// bytes (1 to 4 bytes are valid in the first word). After the first read all bytes are
// valid so this two bits are reset to zero.
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxPointerLSB_rst[1:0] <=#Tp 0;
else
if(TxEn & TxEn_q & TxPointerRead)
TxPointerLSB_rst[1:0] <=#Tp ram_do[1:0];
else
if(MasterWbTX & m_wb_ack_i) // After first access pointer is word alligned
TxPointerLSB_rst[1:0] <=#Tp 0;
end
reg [3:0] RxByteSel;
wire MasterAccessFinished;
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
BlockingIncrementTxPointer <=#Tp 0;
else
if(MasterAccessFinished)
BlockingIncrementTxPointer <=#Tp 0;
else
if(IncrTxPointer)
BlockingIncrementTxPointer <=#Tp 1'b1;
end
wire TxBufferAlmostFull;
wire TxBufferFull;
wire TxBufferEmpty;
wire TxBufferAlmostEmpty;
wire SetReadTxDataFromMemory;
reg BlockReadTxDataFromMemory;
assign SetReadTxDataFromMemory = TxEn & TxEn_q & TxPointerRead;
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
ReadTxDataFromMemory <=#Tp 1'b0;
else
if(TxLengthEq0 | TxAbortPulse | TxRetryPulse)
ReadTxDataFromMemory <=#Tp 1'b0;
else
if(SetReadTxDataFromMemory)
ReadTxDataFromMemory <=#Tp 1'b1;
end
reg tx_burst_en;
reg rx_burst_en;
wire ReadTxDataFromMemory_2 = ReadTxDataFromMemory & ~BlockReadTxDataFromMemory;
wire tx_burst = ReadTxDataFromMemory_2 & tx_burst_en;
wire [31:0] TxData_wb;
wire ReadTxDataFromFifo_wb;
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
BlockReadTxDataFromMemory <=#Tp 1'b0;
else
if((TxBufferAlmostFull | TxLength <= 4)& MasterWbTX & (~cyc_cleared) & (!(TxAbortPacket_NotCleared | TxRetryPacket_NotCleared)))
BlockReadTxDataFromMemory <=#Tp 1'b1;
else
if(ReadTxDataFromFifo_wb | TxDonePacket | TxAbortPacket | TxRetryPacket)
BlockReadTxDataFromMemory <=#Tp 1'b0;
end
assign MasterAccessFinished = m_wb_ack_i | m_wb_err_i;
wire [`ETH_TX_FIFO_CNT_WIDTH-1:0] txfifo_cnt;
wire [`ETH_RX_FIFO_CNT_WIDTH-1:0] rxfifo_cnt;
reg [`ETH_BURST_CNT_WIDTH-1:0] tx_burst_cnt;
reg [`ETH_BURST_CNT_WIDTH-1:0] rx_burst_cnt;
wire rx_burst;
wire enough_data_in_rxfifo_for_burst;
wire enough_data_in_rxfifo_for_burst_plus1;
// Enabling master wishbone access to the memory for two devices TX and RX.
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
begin
MasterWbTX <=#Tp 1'b0;
MasterWbRX <=#Tp 1'b0;
m_wb_adr_o <=#Tp 30'h0;
m_wb_cyc_o <=#Tp 1'b0;
m_wb_we_o <=#Tp 1'b0;
m_wb_sel_o <=#Tp 4'h0;
cyc_cleared<=#Tp 1'b0;
tx_burst_cnt<=#Tp 0;
rx_burst_cnt<=#Tp 0;
IncrTxPointer<=#Tp 1'b0;
tx_burst_en<=#Tp 1'b1;
rx_burst_en<=#Tp 1'b0;
`ifdef ETH_WISHBONE_B3
m_wb_cti_o <=#Tp 3'b0;
`endif
end
else
begin
// Switching between two stages depends on enable signals
casex ({MasterWbTX, MasterWbRX, ReadTxDataFromMemory_2, WriteRxDataToMemory, MasterAccessFinished, cyc_cleared, tx_burst, rx_burst}) // synopsys parallel_case
8'b00_10_00_10, // Idle and MRB needed
8'b10_1x_10_1x, // MRB continues
8'b10_10_01_10, // Clear (previously MR) and MRB needed
8'b01_1x_01_1x : // Clear (previously MW) and MRB needed
begin
MasterWbTX <=#Tp 1'b1; // tx burst
MasterWbRX <=#Tp 1'b0;
m_wb_cyc_o <=#Tp 1'b1;
m_wb_we_o <=#Tp 1'b0;
m_wb_sel_o <=#Tp 4'hf;
cyc_cleared<=#Tp 1'b0;
IncrTxPointer<=#Tp 1'b1;
tx_burst_cnt <=#Tp tx_burst_cnt+3'h1;
if(tx_burst_cnt==0)
m_wb_adr_o <=#Tp TxPointerMSB;
else
m_wb_adr_o <=#Tp m_wb_adr_o+1'b1;
if(tx_burst_cnt==(`ETH_BURST_LENGTH-1))
begin
tx_burst_en<=#Tp 1'b0;
`ifdef ETH_WISHBONE_B3
m_wb_cti_o <=#Tp 3'b111;
`endif
end
else
begin
`ifdef ETH_WISHBONE_B3
m_wb_cti_o <=#Tp 3'b010;
`endif
end
end
8'b00_x1_00_x1, // Idle and MWB needed
8'b01_x1_10_x1, // MWB continues
8'b01_01_01_01, // Clear (previously MW) and MWB needed
8'b10_x1_01_x1 : // Clear (previously MR) and MWB needed
begin
MasterWbTX <=#Tp 1'b0; // rx burst
MasterWbRX <=#Tp 1'b1;
m_wb_cyc_o <=#Tp 1'b1;
m_wb_we_o <=#Tp 1'b1;
m_wb_sel_o <=#Tp RxByteSel;
IncrTxPointer<=#Tp 1'b0;
cyc_cleared<=#Tp 1'b0;
rx_burst_cnt <=#Tp rx_burst_cnt+3'h1;
if(rx_burst_cnt==0)
m_wb_adr_o <=#Tp RxPointerMSB;
else
m_wb_adr_o <=#Tp m_wb_adr_o+1'b1;
if(rx_burst_cnt==(`ETH_BURST_LENGTH-1))
begin
rx_burst_en<=#Tp 1'b0;
`ifdef ETH_WISHBONE_B3
m_wb_cti_o <=#Tp 3'b111;
`endif
end
else
begin
`ifdef ETH_WISHBONE_B3
m_wb_cti_o <=#Tp 3'b010;
`endif
end
end
8'b00_x1_00_x0 : // idle and MW is needed (data write to rx buffer)
begin
MasterWbTX <=#Tp 1'b0;
MasterWbRX <=#Tp 1'b1;
m_wb_adr_o <=#Tp RxPointerMSB;
m_wb_cyc_o <=#Tp 1'b1;
m_wb_we_o <=#Tp 1'b1;
m_wb_sel_o <=#Tp RxByteSel;
IncrTxPointer<=#Tp 1'b0;
end
8'b00_10_00_00 : // idle and MR is needed (data read from tx buffer)
begin
MasterWbTX <=#Tp 1'b1;
MasterWbRX <=#Tp 1'b0;
m_wb_adr_o <=#Tp TxPointerMSB;
m_wb_cyc_o <=#Tp 1'b1;
m_wb_we_o <=#Tp 1'b0;
m_wb_sel_o <=#Tp 4'hf;
IncrTxPointer<=#Tp 1'b1;
end
8'b10_10_01_00, // MR and MR is needed (data read from tx buffer)
8'b01_1x_01_0x : // MW and MR is needed (data read from tx buffer)
begin
MasterWbTX <=#Tp 1'b1;
MasterWbRX <=#Tp 1'b0;
m_wb_adr_o <=#Tp TxPointerMSB;
m_wb_cyc_o <=#Tp 1'b1;
m_wb_we_o <=#Tp 1'b0;
m_wb_sel_o <=#Tp 4'hf;
cyc_cleared<=#Tp 1'b0;
IncrTxPointer<=#Tp 1'b1;
end
8'b01_01_01_00, // MW and MW needed (data write to rx buffer)
8'b10_x1_01_x0 : // MR and MW is needed (data write to rx buffer)
begin
MasterWbTX <=#Tp 1'b0;
MasterWbRX <=#Tp 1'b1;
m_wb_adr_o <=#Tp RxPointerMSB;
m_wb_cyc_o <=#Tp 1'b1;
m_wb_we_o <=#Tp 1'b1;
m_wb_sel_o <=#Tp RxByteSel;
cyc_cleared<=#Tp 1'b0;
IncrTxPointer<=#Tp 1'b0;
end
8'b01_01_10_00, // MW and MW needed (cycle is cleared between previous and next access)
8'b01_1x_10_x0, // MW and MW or MR or MRB needed (cycle is cleared between previous and next access)
8'b10_10_10_00, // MR and MR needed (cycle is cleared between previous and next access)
8'b10_x1_10_0x : // MR and MR or MW or MWB (cycle is cleared between previous and next access)
begin
m_wb_cyc_o <=#Tp 1'b0; // whatever and master read or write is needed. We need to clear m_wb_cyc_o before next access is started
cyc_cleared<=#Tp 1'b1;
IncrTxPointer<=#Tp 1'b0;
tx_burst_cnt<=#Tp 0;
tx_burst_en<=#Tp txfifo_cnt<(`ETH_TX_FIFO_DEPTH-`ETH_BURST_LENGTH) & (TxLength>(`ETH_BURST_LENGTH*4+4));
rx_burst_cnt<=#Tp 0;
rx_burst_en<=#Tp MasterWbRX ? enough_data_in_rxfifo_for_burst_plus1 : enough_data_in_rxfifo_for_burst; // Counter is not decremented, yet, so plus1 is used.
`ifdef ETH_WISHBONE_B3
m_wb_cti_o <=#Tp 3'b0;
`endif
end
8'bxx_00_10_00, // whatever and no master read or write is needed (ack or err comes finishing previous access)
8'bxx_00_01_00 : // Between cyc_cleared request was cleared
begin
MasterWbTX <=#Tp 1'b0;
MasterWbRX <=#Tp 1'b0;
m_wb_cyc_o <=#Tp 1'b0;
cyc_cleared<=#Tp 1'b0;
IncrTxPointer<=#Tp 1'b0;
rx_burst_cnt<=#Tp 0;
rx_burst_en<=#Tp MasterWbRX ? enough_data_in_rxfifo_for_burst_plus1 : enough_data_in_rxfifo_for_burst; // Counter is not decremented, yet, so plus1 is used.
`ifdef ETH_WISHBONE_B3
m_wb_cti_o <=#Tp 3'b0;
`endif
end
8'b00_00_00_00: // whatever and no master read or write is needed (ack or err comes finishing previous access)
begin
tx_burst_cnt<=#Tp 0;
tx_burst_en<=#Tp txfifo_cnt<(`ETH_TX_FIFO_DEPTH-`ETH_BURST_LENGTH) & (TxLength>(`ETH_BURST_LENGTH*4+4));
end
default: // Don't touch
begin
MasterWbTX <=#Tp MasterWbTX;
MasterWbRX <=#Tp MasterWbRX;
m_wb_cyc_o <=#Tp m_wb_cyc_o;
m_wb_sel_o <=#Tp m_wb_sel_o;
IncrTxPointer<=#Tp IncrTxPointer;
end
endcase
end
end
wire TxFifoClear;
assign TxFifoClear = (TxAbortPacket | TxRetryPacket);
eth_fifo #(`ETH_TX_FIFO_DATA_WIDTH, `ETH_TX_FIFO_DEPTH, `ETH_TX_FIFO_CNT_WIDTH)
tx_fifo ( .data_in(m_wb_dat_i), .data_out(TxData_wb),
.clk(WB_CLK_I), .reset(Reset),
.write(MasterWbTX & m_wb_ack_i), .read(ReadTxDataFromFifo_wb & ~TxBufferEmpty),
.clear(TxFifoClear), .full(TxBufferFull),
.almost_full(TxBufferAlmostFull), .almost_empty(TxBufferAlmostEmpty),
.empty(TxBufferEmpty), .cnt(txfifo_cnt)
);
reg StartOccured;
reg TxStartFrm_sync1;
reg TxStartFrm_sync2;
reg TxStartFrm_syncb1;
reg TxStartFrm_syncb2;
// Start: Generation of the TxStartFrm_wb which is then synchronized to the MTxClk
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxStartFrm_wb <=#Tp 1'b0;
else
if(TxBDReady & ~StartOccured & (TxBufferFull | TxLengthEq0))
TxStartFrm_wb <=#Tp 1'b1;
else
if(TxStartFrm_syncb2)
TxStartFrm_wb <=#Tp 1'b0;
end
// StartOccured: TxStartFrm_wb occurs only ones at the beginning. Then it's blocked.
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
StartOccured <=#Tp 1'b0;
else
if(TxStartFrm_wb)
StartOccured <=#Tp 1'b1;
else
if(ResetTxBDReady)
StartOccured <=#Tp 1'b0;
end
// Synchronizing TxStartFrm_wb to MTxClk
always @ (posedge MTxClk or posedge Reset)
begin
if(Reset)
TxStartFrm_sync1 <=#Tp 1'b0;
else
TxStartFrm_sync1 <=#Tp TxStartFrm_wb;
end
always @ (posedge MTxClk or posedge Reset)
begin
if(Reset)
TxStartFrm_sync2 <=#Tp 1'b0;
else
TxStartFrm_sync2 <=#Tp TxStartFrm_sync1;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxStartFrm_syncb1 <=#Tp 1'b0;
else
TxStartFrm_syncb1 <=#Tp TxStartFrm_sync2;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxStartFrm_syncb2 <=#Tp 1'b0;
else
TxStartFrm_syncb2 <=#Tp TxStartFrm_syncb1;
end
always @ (posedge MTxClk or posedge Reset)
begin
if(Reset)
TxStartFrm <=#Tp 1'b0;
else
if(TxStartFrm_sync2)
TxStartFrm <=#Tp 1'b1;
else
if(TxUsedData_q | ~TxStartFrm_sync2 & (TxRetry & (~TxRetry_q) | TxAbort & (~TxAbort_q)))
TxStartFrm <=#Tp 1'b0;
end
// End: Generation of the TxStartFrm_wb which is then synchronized to the MTxClk
// TxEndFrm_wb: indicator of the end of frame
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxEndFrm_wb <=#Tp 1'b0;
else
if(TxLengthEq0 & TxBufferAlmostEmpty & TxUsedData)
TxEndFrm_wb <=#Tp 1'b1;
else
if(TxRetryPulse | TxDonePulse | TxAbortPulse)
TxEndFrm_wb <=#Tp 1'b0;
end
// Marks which bytes are valid within the word.
assign TxValidBytes = TxLengthLt4 ? TxLength[1:0] : 2'b0;
reg LatchValidBytes;
reg LatchValidBytes_q;
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
LatchValidBytes <=#Tp 1'b0;
else
if(TxLengthLt4 & TxBDReady)
LatchValidBytes <=#Tp 1'b1;
else
LatchValidBytes <=#Tp 1'b0;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
LatchValidBytes_q <=#Tp 1'b0;
else
LatchValidBytes_q <=#Tp LatchValidBytes;
end
// Latching valid bytes
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxValidBytesLatched <=#Tp 2'h0;
else
if(LatchValidBytes & ~LatchValidBytes_q)
TxValidBytesLatched <=#Tp TxValidBytes;
else
if(TxRetryPulse | TxDonePulse | TxAbortPulse)
TxValidBytesLatched <=#Tp 2'h0;
end
assign TxIRQEn = TxStatus[14];
assign WrapTxStatusBit = TxStatus[13];
assign PerPacketPad = TxStatus[12];
assign PerPacketCrcEn = TxStatus[11];
assign RxIRQEn = RxStatus[14];
assign WrapRxStatusBit = RxStatus[13];
// Temporary Tx and Rx buffer descriptor address
assign TempTxBDAddress[7:1] = {7{ TxStatusWrite & ~WrapTxStatusBit}} & (TxBDAddress + 1'b1) ; // Tx BD increment or wrap (last BD)
assign TempRxBDAddress[7:1] = {7{ WrapRxStatusBit}} & (r_TxBDNum[6:0]) | // Using first Rx BD
{7{~WrapRxStatusBit}} & (RxBDAddress + 1'b1) ; // Using next Rx BD (incremenrement address)
// Latching Tx buffer descriptor address
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxBDAddress <=#Tp 7'h0;
else if (r_TxEn & (~r_TxEn_q))
TxBDAddress <=#Tp 7'h0;
else if (TxStatusWrite)
TxBDAddress <=#Tp TempTxBDAddress;
end
// Latching Rx buffer descriptor address
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
RxBDAddress <=#Tp 7'h0;
else if(r_RxEn & (~r_RxEn_q))
RxBDAddress <=#Tp r_TxBDNum[6:0];
else if(RxStatusWrite)
RxBDAddress <=#Tp TempRxBDAddress;
end
wire [8:0] TxStatusInLatched = {TxUnderRun, RetryCntLatched[3:0], RetryLimit, LateCollLatched, DeferLatched, CarrierSenseLost};
assign RxBDDataIn = {LatchedRxLength, 1'b0, RxStatus, 4'h0, RxStatusInLatched};
assign TxBDDataIn = {LatchedTxLength, 1'b0, TxStatus, 2'h0, TxStatusInLatched};
// Signals used for various purposes
assign TxRetryPulse = TxRetry_wb & ~TxRetry_wb_q;
assign TxDonePulse = TxDone_wb & ~TxDone_wb_q;
assign TxAbortPulse = TxAbort_wb & ~TxAbort_wb_q;
// Generating delayed signals
always @ (posedge MTxClk or posedge Reset)
begin
if(Reset)
begin
TxAbort_q <=#Tp 1'b0;
TxRetry_q <=#Tp 1'b0;
TxUsedData_q <=#Tp 1'b0;
end
else
begin
TxAbort_q <=#Tp TxAbort;
TxRetry_q <=#Tp TxRetry;
TxUsedData_q <=#Tp TxUsedData;
end
end
// Generating delayed signals
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
begin
TxDone_wb_q <=#Tp 1'b0;
TxAbort_wb_q <=#Tp 1'b0;
TxRetry_wb_q <=#Tp 1'b0;
end
else
begin
TxDone_wb_q <=#Tp TxDone_wb;
TxAbort_wb_q <=#Tp TxAbort_wb;
TxRetry_wb_q <=#Tp TxRetry_wb;
end
end
reg TxAbortPacketBlocked;
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxAbortPacket <=#Tp 1'b0;
else
if(TxAbort_wb & (~tx_burst_en) & MasterWbTX & MasterAccessFinished & (~TxAbortPacketBlocked) |
TxAbort_wb & (~MasterWbTX) & (~TxAbortPacketBlocked))
TxAbortPacket <=#Tp 1'b1;
else
TxAbortPacket <=#Tp 1'b0;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxAbortPacket_NotCleared <=#Tp 1'b0;
else
if(TxEn & TxEn_q & TxAbortPacket_NotCleared)
TxAbortPacket_NotCleared <=#Tp 1'b0;
else
if(TxAbort_wb & (~tx_burst_en) & MasterWbTX & MasterAccessFinished & (~TxAbortPacketBlocked) |
TxAbort_wb & (~MasterWbTX) & (~TxAbortPacketBlocked))
TxAbortPacket_NotCleared <=#Tp 1'b1;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxAbortPacketBlocked <=#Tp 1'b0;
else
if(!TxAbort_wb & TxAbort_wb_q)
TxAbortPacketBlocked <=#Tp 1'b0;
else
if(TxAbortPacket)
TxAbortPacketBlocked <=#Tp 1'b1;
end
reg TxRetryPacketBlocked;
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxRetryPacket <=#Tp 1'b0;
else
if(TxRetry_wb & !tx_burst_en & MasterWbTX & MasterAccessFinished & !TxRetryPacketBlocked |
TxRetry_wb & !MasterWbTX & !TxRetryPacketBlocked)
TxRetryPacket <=#Tp 1'b1;
else
TxRetryPacket <=#Tp 1'b0;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxRetryPacket_NotCleared <=#Tp 1'b0;
else
if(StartTxBDRead)
TxRetryPacket_NotCleared <=#Tp 1'b0;
else
if(TxRetry_wb & !tx_burst_en & MasterWbTX & MasterAccessFinished & !TxRetryPacketBlocked |
TxRetry_wb & !MasterWbTX & !TxRetryPacketBlocked)
TxRetryPacket_NotCleared <=#Tp 1'b1;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxRetryPacketBlocked <=#Tp 1'b0;
else
if(!TxRetry_wb & TxRetry_wb_q)
TxRetryPacketBlocked <=#Tp 1'b0;
else
if(TxRetryPacket)
TxRetryPacketBlocked <=#Tp 1'b1;
end
reg TxDonePacketBlocked;
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxDonePacket <=#Tp 1'b0;
else
if(TxDone_wb & !tx_burst_en & MasterWbTX & MasterAccessFinished & !TxDonePacketBlocked |
TxDone_wb & !MasterWbTX & !TxDonePacketBlocked)
TxDonePacket <=#Tp 1'b1;
else
TxDonePacket <=#Tp 1'b0;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxDonePacket_NotCleared <=#Tp 1'b0;
else
if(TxEn & TxEn_q & TxDonePacket_NotCleared)
TxDonePacket_NotCleared <=#Tp 1'b0;
else
if(TxDone_wb & !tx_burst_en & MasterWbTX & MasterAccessFinished & (~TxDonePacketBlocked) |
TxDone_wb & !MasterWbTX & (~TxDonePacketBlocked))
TxDonePacket_NotCleared <=#Tp 1'b1;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxDonePacketBlocked <=#Tp 1'b0;
else
if(!TxDone_wb & TxDone_wb_q)
TxDonePacketBlocked <=#Tp 1'b0;
else
if(TxDonePacket)
TxDonePacketBlocked <=#Tp 1'b1;
end
// Indication of the last word
always @ (posedge MTxClk or posedge Reset)
begin
if(Reset)
LastWord <=#Tp 1'b0;
else
if((TxEndFrm | TxAbort | TxRetry) & Flop)
LastWord <=#Tp 1'b0;
else
if(TxUsedData & Flop & TxByteCnt == 2'h3)
LastWord <=#Tp TxEndFrm_wb;
end
// Tx end frame generation
always @ (posedge MTxClk or posedge Reset)
begin
if(Reset)
TxEndFrm <=#Tp 1'b0;
else
if(Flop & TxEndFrm | TxAbort | TxRetry_q)
TxEndFrm <=#Tp 1'b0;
else
if(Flop & LastWord)
begin
case (TxValidBytesLatched) // synopsys parallel_case
1 : TxEndFrm <=#Tp TxByteCnt == 2'h0;
2 : TxEndFrm <=#Tp TxByteCnt == 2'h1;
3 : TxEndFrm <=#Tp TxByteCnt == 2'h2;
0 : TxEndFrm <=#Tp TxByteCnt == 2'h3;
default : TxEndFrm <=#Tp 1'b0;
endcase
end
end
// Tx data selection (latching)
always @ (posedge MTxClk or posedge Reset)
begin
if(Reset)
TxData <=#Tp 0;
else
if(TxStartFrm_sync2 & ~TxStartFrm)
case(TxPointerLSB) // synopsys parallel_case
2'h0 : TxData <=#Tp TxData_wb[31:24]; // Big Endian Byte Ordering
2'h1 : TxData <=#Tp TxData_wb[23:16]; // Big Endian Byte Ordering
2'h2 : TxData <=#Tp TxData_wb[15:08]; // Big Endian Byte Ordering
2'h3 : TxData <=#Tp TxData_wb[07:00]; // Big Endian Byte Ordering
endcase
else
if(TxStartFrm & TxUsedData & TxPointerLSB==2'h3)
TxData <=#Tp TxData_wb[31:24]; // Big Endian Byte Ordering
else
if(TxUsedData & Flop)
begin
case(TxByteCnt) // synopsys parallel_case
0 : TxData <=#Tp TxDataLatched[31:24]; // Big Endian Byte Ordering
1 : TxData <=#Tp TxDataLatched[23:16];
2 : TxData <=#Tp TxDataLatched[15:8];
3 : TxData <=#Tp TxDataLatched[7:0];
endcase
end
end
// Latching tx data
always @ (posedge MTxClk or posedge Reset)
begin
if(Reset)
TxDataLatched[31:0] <=#Tp 32'h0;
else
if(TxStartFrm_sync2 & ~TxStartFrm | TxUsedData & Flop & TxByteCnt == 2'h3 | TxStartFrm & TxUsedData & Flop & TxByteCnt == 2'h0)
TxDataLatched[31:0] <=#Tp TxData_wb[31:0];
end
// Tx under run
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxUnderRun_wb <=#Tp 1'b0;
else
if(TxAbortPulse)
TxUnderRun_wb <=#Tp 1'b0;
else
if(TxBufferEmpty & ReadTxDataFromFifo_wb)
TxUnderRun_wb <=#Tp 1'b1;
end
reg TxUnderRun_sync1;
// Tx under run
always @ (posedge MTxClk or posedge Reset)
begin
if(Reset)
TxUnderRun_sync1 <=#Tp 1'b0;
else
if(TxUnderRun_wb)
TxUnderRun_sync1 <=#Tp 1'b1;
else
if(BlockingTxStatusWrite_sync2)
TxUnderRun_sync1 <=#Tp 1'b0;
end
// Tx under run
always @ (posedge MTxClk or posedge Reset)
begin
if(Reset)
TxUnderRun <=#Tp 1'b0;
else
if(BlockingTxStatusWrite_sync2)
TxUnderRun <=#Tp 1'b0;
else
if(TxUnderRun_sync1)
TxUnderRun <=#Tp 1'b1;
end
// Tx Byte counter
always @ (posedge MTxClk or posedge Reset)
begin
if(Reset)
TxByteCnt <=#Tp 2'h0;
else
if(TxAbort_q | TxRetry_q)
TxByteCnt <=#Tp 2'h0;
else
if(TxStartFrm & ~TxUsedData)
case(TxPointerLSB) // synopsys parallel_case
2'h0 : TxByteCnt <=#Tp 2'h1;
2'h1 : TxByteCnt <=#Tp 2'h2;
2'h2 : TxByteCnt <=#Tp 2'h3;
2'h3 : TxByteCnt <=#Tp 2'h0;
endcase
else
if(TxUsedData & Flop)
TxByteCnt <=#Tp TxByteCnt + 1'b1;
end
// Start: Generation of the ReadTxDataFromFifo_tck signal and synchronization to the WB_CLK_I
reg ReadTxDataFromFifo_sync1;
reg ReadTxDataFromFifo_sync2;
reg ReadTxDataFromFifo_sync3;
reg ReadTxDataFromFifo_syncb1;
reg ReadTxDataFromFifo_syncb2;
reg ReadTxDataFromFifo_syncb3;
always @ (posedge MTxClk or posedge Reset)
begin
if(Reset)
ReadTxDataFromFifo_tck <=#Tp 1'b0;
else
if(TxStartFrm_sync2 & ~TxStartFrm | TxUsedData & Flop & TxByteCnt == 2'h3 & ~LastWord | TxStartFrm & TxUsedData & Flop & TxByteCnt == 2'h0)
ReadTxDataFromFifo_tck <=#Tp 1'b1;
else
if(ReadTxDataFromFifo_syncb2 & ~ReadTxDataFromFifo_syncb3)
ReadTxDataFromFifo_tck <=#Tp 1'b0;
end
// Synchronizing TxStartFrm_wb to MTxClk
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
ReadTxDataFromFifo_sync1 <=#Tp 1'b0;
else
ReadTxDataFromFifo_sync1 <=#Tp ReadTxDataFromFifo_tck;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
ReadTxDataFromFifo_sync2 <=#Tp 1'b0;
else
ReadTxDataFromFifo_sync2 <=#Tp ReadTxDataFromFifo_sync1;
end
always @ (posedge MTxClk or posedge Reset)
begin
if(Reset)
ReadTxDataFromFifo_syncb1 <=#Tp 1'b0;
else
ReadTxDataFromFifo_syncb1 <=#Tp ReadTxDataFromFifo_sync2;
end
always @ (posedge MTxClk or posedge Reset)
begin
if(Reset)
ReadTxDataFromFifo_syncb2 <=#Tp 1'b0;
else
ReadTxDataFromFifo_syncb2 <=#Tp ReadTxDataFromFifo_syncb1;
end
always @ (posedge MTxClk or posedge Reset)
begin
if(Reset)
ReadTxDataFromFifo_syncb3 <=#Tp 1'b0;
else
ReadTxDataFromFifo_syncb3 <=#Tp ReadTxDataFromFifo_syncb2;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
ReadTxDataFromFifo_sync3 <=#Tp 1'b0;
else
ReadTxDataFromFifo_sync3 <=#Tp ReadTxDataFromFifo_sync2;
end
assign ReadTxDataFromFifo_wb = ReadTxDataFromFifo_sync2 & ~ReadTxDataFromFifo_sync3;
// End: Generation of the ReadTxDataFromFifo_tck signal and synchronization to the WB_CLK_I
// Synchronizing TxRetry signal (synchronized to WISHBONE clock)
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxRetrySync1 <=#Tp 1'b0;
else
TxRetrySync1 <=#Tp TxRetry;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxRetry_wb <=#Tp 1'b0;
else
TxRetry_wb <=#Tp TxRetrySync1;
end
// Synchronized TxDone_wb signal (synchronized to WISHBONE clock)
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxDoneSync1 <=#Tp 1'b0;
else
TxDoneSync1 <=#Tp TxDone;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxDone_wb <=#Tp 1'b0;
else
TxDone_wb <=#Tp TxDoneSync1;
end
// Synchronizing TxAbort signal (synchronized to WISHBONE clock)
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxAbortSync1 <=#Tp 1'b0;
else
TxAbortSync1 <=#Tp TxAbort;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxAbort_wb <=#Tp 1'b0;
else
TxAbort_wb <=#Tp TxAbortSync1;
end
reg RxAbortSync1;
reg RxAbortSync2;
reg RxAbortSync3;
reg RxAbortSync4;
reg RxAbortSyncb1;
reg RxAbortSyncb2;
assign StartRxBDRead = RxStatusWrite | RxAbortSync3 & ~RxAbortSync4 | r_RxEn & ~r_RxEn_q;
// Reading the Rx buffer descriptor
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
RxBDRead <=#Tp 1'b0;
else
if(StartRxBDRead & ~RxReady)
RxBDRead <=#Tp 1'b1;
else
if(RxBDReady)
RxBDRead <=#Tp 1'b0;
end
// Reading of the next receive buffer descriptor starts after reception status is
// written to the previous one.
// Latching READY status of the Rx buffer descriptor
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
RxBDReady <=#Tp 1'b0;
else
if(RxPointerRead)
RxBDReady <=#Tp 1'b0;
else
if(RxEn & RxEn_q & RxBDRead)
RxBDReady <=#Tp ram_do[15]; // RxBDReady is sampled only once at the beginning
end
// Latching Rx buffer descriptor status
// Data is avaliable one cycle after the access is started (at that time signal RxEn is not active)
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
RxStatus <=#Tp 2'h0;
else
if(RxEn & RxEn_q & RxBDRead)
RxStatus <=#Tp ram_do[14:13];
end
// RxReady generation
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
RxReady <=#Tp 1'b0;
else
if(ShiftEnded | RxAbortSync2 & ~RxAbortSync3 | ~r_RxEn & r_RxEn_q)
RxReady <=#Tp 1'b0;
else
if(RxEn & RxEn_q & RxPointerRead)
RxReady <=#Tp 1'b1;
end
// Reading Rx BD pointer
assign StartRxPointerRead = RxBDRead & RxBDReady;
// Reading Tx BD Pointer
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
RxPointerRead <=#Tp 1'b0;
else
if(StartRxPointerRead)
RxPointerRead <=#Tp 1'b1;
else
if(RxEn & RxEn_q)
RxPointerRead <=#Tp 1'b0;
end
//Latching Rx buffer pointer from buffer descriptor;
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
RxPointerMSB <=#Tp 30'h0;
else
if(RxEn & RxEn_q & RxPointerRead)
RxPointerMSB <=#Tp ram_do[31:2];
else
if(MasterWbRX & m_wb_ack_i)
RxPointerMSB <=#Tp RxPointerMSB + 1'b1; // Word access (always word access. m_wb_sel_o are used for selecting bytes)
end
//Latching last addresses from buffer descriptor (used as byte-half-word indicator);
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
RxPointerLSB_rst[1:0] <=#Tp 0;
else
if(MasterWbRX & m_wb_ack_i) // After first write all RxByteSel are active
RxPointerLSB_rst[1:0] <=#Tp 0;
else
if(RxEn & RxEn_q & RxPointerRead)
RxPointerLSB_rst[1:0] <=#Tp ram_do[1:0];
end
always @ (RxPointerLSB_rst)
begin
case(RxPointerLSB_rst[1:0]) // synopsys parallel_case
2'h0 : RxByteSel[3:0] = 4'hf;
2'h1 : RxByteSel[3:0] = 4'h7;
2'h2 : RxByteSel[3:0] = 4'h3;
2'h3 : RxByteSel[3:0] = 4'h1;
endcase
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
RxEn_needed <=#Tp 1'b0;
else
if(~RxReady & r_RxEn & WbEn & ~WbEn_q)
RxEn_needed <=#Tp 1'b1;
else
if(RxPointerRead & RxEn & RxEn_q)
RxEn_needed <=#Tp 1'b0;
end
// Reception status is written back to the buffer descriptor after the end of frame is detected.
assign RxStatusWrite = ShiftEnded & RxEn & RxEn_q;
reg RxEnableWindow;
// Indicating that last byte is being reveived
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
LastByteIn <=#Tp 1'b0;
else
if(ShiftWillEnd & (&RxByteCnt) | RxAbort)
LastByteIn <=#Tp 1'b0;
else
if(RxValid & RxReady & RxEndFrm & ~(&RxByteCnt) & RxEnableWindow)
LastByteIn <=#Tp 1'b1;
end
reg ShiftEnded_rck;
reg ShiftEndedSync1;
reg ShiftEndedSync2;
reg ShiftEndedSync3;
reg ShiftEndedSync_c1;
reg ShiftEndedSync_c2;
wire StartShiftWillEnd;
assign StartShiftWillEnd = LastByteIn | RxValid & RxEndFrm & (&RxByteCnt) & RxEnableWindow;
// Indicating that data reception will end
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
ShiftWillEnd <=#Tp 1'b0;
else
if(ShiftEnded_rck | RxAbort)
ShiftWillEnd <=#Tp 1'b0;
else
if(StartShiftWillEnd)
ShiftWillEnd <=#Tp 1'b1;
end
// Receive byte counter
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
RxByteCnt <=#Tp 2'h0;
else
if(ShiftEnded_rck | RxAbort)
RxByteCnt <=#Tp 2'h0;
else
if(RxValid & RxStartFrm & RxReady)
case(RxPointerLSB_rst) // synopsys parallel_case
2'h0 : RxByteCnt <=#Tp 2'h1;
2'h1 : RxByteCnt <=#Tp 2'h2;
2'h2 : RxByteCnt <=#Tp 2'h3;
2'h3 : RxByteCnt <=#Tp 2'h0;
endcase
else
if(RxValid & RxEnableWindow & RxReady | LastByteIn)
RxByteCnt <=#Tp RxByteCnt + 1'b1;
end
// Indicates how many bytes are valid within the last word
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
RxValidBytes <=#Tp 2'h1;
else
if(RxValid & RxStartFrm)
case(RxPointerLSB_rst) // synopsys parallel_case
2'h0 : RxValidBytes <=#Tp 2'h1;
2'h1 : RxValidBytes <=#Tp 2'h2;
2'h2 : RxValidBytes <=#Tp 2'h3;
2'h3 : RxValidBytes <=#Tp 2'h0;
endcase
else
if(RxValid & ~LastByteIn & ~RxStartFrm & RxEnableWindow)
RxValidBytes <=#Tp RxValidBytes + 1'b1;
end
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
RxDataLatched1 <=#Tp 24'h0;
else
if(RxValid & RxReady & ~LastByteIn)
if(RxStartFrm)
begin
case(RxPointerLSB_rst) // synopsys parallel_case
2'h0: RxDataLatched1[31:24] <=#Tp RxData; // Big Endian Byte Ordering
2'h1: RxDataLatched1[23:16] <=#Tp RxData;
2'h2: RxDataLatched1[15:8] <=#Tp RxData;
2'h3: RxDataLatched1 <=#Tp RxDataLatched1;
endcase
end
else if (RxEnableWindow)
begin
case(RxByteCnt) // synopsys parallel_case
2'h0: RxDataLatched1[31:24] <=#Tp RxData; // Big Endian Byte Ordering
2'h1: RxDataLatched1[23:16] <=#Tp RxData;
2'h2: RxDataLatched1[15:8] <=#Tp RxData;
2'h3: RxDataLatched1 <=#Tp RxDataLatched1;
endcase
end
end
wire SetWriteRxDataToFifo;
// Assembling data that will be written to the rx_fifo
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
RxDataLatched2 <=#Tp 32'h0;
else
if(SetWriteRxDataToFifo & ~ShiftWillEnd)
RxDataLatched2 <=#Tp {RxDataLatched1[31:8], RxData}; // Big Endian Byte Ordering
else
if(SetWriteRxDataToFifo & ShiftWillEnd)
case(RxValidBytes) // synopsys parallel_case
0 : RxDataLatched2 <=#Tp {RxDataLatched1[31:8], RxData}; // Big Endian Byte Ordering
1 : RxDataLatched2 <=#Tp {RxDataLatched1[31:24], 24'h0};
2 : RxDataLatched2 <=#Tp {RxDataLatched1[31:16], 16'h0};
3 : RxDataLatched2 <=#Tp {RxDataLatched1[31:8], 8'h0};
endcase
end
reg WriteRxDataToFifoSync1;
reg WriteRxDataToFifoSync2;
reg WriteRxDataToFifoSync3;
// Indicating start of the reception process
assign SetWriteRxDataToFifo = (RxValid & RxReady & ~RxStartFrm & RxEnableWindow & (&RxByteCnt)) |
(RxValid & RxReady & RxStartFrm & (&RxPointerLSB_rst)) |
(ShiftWillEnd & LastByteIn & (&RxByteCnt));
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
WriteRxDataToFifo <=#Tp 1'b0;
else
if(SetWriteRxDataToFifo & ~RxAbort)
WriteRxDataToFifo <=#Tp 1'b1;
else
if(WriteRxDataToFifoSync2 | RxAbort)
WriteRxDataToFifo <=#Tp 1'b0;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
WriteRxDataToFifoSync1 <=#Tp 1'b0;
else
if(WriteRxDataToFifo)
WriteRxDataToFifoSync1 <=#Tp 1'b1;
else
WriteRxDataToFifoSync1 <=#Tp 1'b0;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
WriteRxDataToFifoSync2 <=#Tp 1'b0;
else
WriteRxDataToFifoSync2 <=#Tp WriteRxDataToFifoSync1;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
WriteRxDataToFifoSync3 <=#Tp 1'b0;
else
WriteRxDataToFifoSync3 <=#Tp WriteRxDataToFifoSync2;
end
wire WriteRxDataToFifo_wb;
assign WriteRxDataToFifo_wb = WriteRxDataToFifoSync2 & ~WriteRxDataToFifoSync3;
reg LatchedRxStartFrm;
reg SyncRxStartFrm;
reg SyncRxStartFrm_q;
reg SyncRxStartFrm_q2;
wire RxFifoReset;
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
LatchedRxStartFrm <=#Tp 0;
else
if(RxStartFrm & ~SyncRxStartFrm_q)
LatchedRxStartFrm <=#Tp 1;
else
if(SyncRxStartFrm_q)
LatchedRxStartFrm <=#Tp 0;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
SyncRxStartFrm <=#Tp 0;
else
if(LatchedRxStartFrm)
SyncRxStartFrm <=#Tp 1;
else
SyncRxStartFrm <=#Tp 0;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
SyncRxStartFrm_q <=#Tp 0;
else
SyncRxStartFrm_q <=#Tp SyncRxStartFrm;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
SyncRxStartFrm_q2 <=#Tp 0;
else
SyncRxStartFrm_q2 <=#Tp SyncRxStartFrm_q;
end
assign RxFifoReset = SyncRxStartFrm_q & ~SyncRxStartFrm_q2;
eth_fifo #(`ETH_RX_FIFO_DATA_WIDTH, `ETH_RX_FIFO_DEPTH, `ETH_RX_FIFO_CNT_WIDTH)
rx_fifo (.data_in(RxDataLatched2), .data_out(m_wb_dat_o),
.clk(WB_CLK_I), .reset(Reset),
.write(WriteRxDataToFifo_wb & ~RxBufferFull), .read(MasterWbRX & m_wb_ack_i),
.clear(RxFifoReset), .full(RxBufferFull),
.almost_full(), .almost_empty(RxBufferAlmostEmpty),
.empty(RxBufferEmpty), .cnt(rxfifo_cnt)
);
assign enough_data_in_rxfifo_for_burst = rxfifo_cnt>=`ETH_BURST_LENGTH;
assign enough_data_in_rxfifo_for_burst_plus1 = rxfifo_cnt>`ETH_BURST_LENGTH;
assign WriteRxDataToMemory = ~RxBufferEmpty;
assign rx_burst = rx_burst_en & WriteRxDataToMemory;
// Generation of the end-of-frame signal
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
ShiftEnded_rck <=#Tp 1'b0;
else
if(~RxAbort & SetWriteRxDataToFifo & StartShiftWillEnd)
ShiftEnded_rck <=#Tp 1'b1;
else
if(RxAbort | ShiftEndedSync_c1 & ShiftEndedSync_c2)
ShiftEnded_rck <=#Tp 1'b0;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
ShiftEndedSync1 <=#Tp 1'b0;
else
ShiftEndedSync1 <=#Tp ShiftEnded_rck;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
ShiftEndedSync2 <=#Tp 1'b0;
else
ShiftEndedSync2 <=#Tp ShiftEndedSync1;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
ShiftEndedSync3 <=#Tp 1'b0;
else
if(ShiftEndedSync1 & ~ShiftEndedSync2)
ShiftEndedSync3 <=#Tp 1'b1;
else
if(ShiftEnded)
ShiftEndedSync3 <=#Tp 1'b0;
end
// Generation of the end-of-frame signal
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
ShiftEnded <=#Tp 1'b0;
else
if(ShiftEndedSync3 & MasterWbRX & m_wb_ack_i & RxBufferAlmostEmpty & ~ShiftEnded)
ShiftEnded <=#Tp 1'b1;
else
if(RxStatusWrite)
ShiftEnded <=#Tp 1'b0;
end
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
ShiftEndedSync_c1 <=#Tp 1'b0;
else
ShiftEndedSync_c1 <=#Tp ShiftEndedSync2;
end
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
ShiftEndedSync_c2 <=#Tp 1'b0;
else
ShiftEndedSync_c2 <=#Tp ShiftEndedSync_c1;
end
// Generation of the end-of-frame signal
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
RxEnableWindow <=#Tp 1'b0;
else
if(RxStartFrm)
RxEnableWindow <=#Tp 1'b1;
else
if(RxEndFrm | RxAbort)
RxEnableWindow <=#Tp 1'b0;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
RxAbortSync1 <=#Tp 1'b0;
else
RxAbortSync1 <=#Tp RxAbortLatched;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
RxAbortSync2 <=#Tp 1'b0;
else
RxAbortSync2 <=#Tp RxAbortSync1;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
RxAbortSync3 <=#Tp 1'b0;
else
RxAbortSync3 <=#Tp RxAbortSync2;
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
RxAbortSync4 <=#Tp 1'b0;
else
RxAbortSync4 <=#Tp RxAbortSync3;
end
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
RxAbortSyncb1 <=#Tp 1'b0;
else
RxAbortSyncb1 <=#Tp RxAbortSync2;
end
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
RxAbortSyncb2 <=#Tp 1'b0;
else
RxAbortSyncb2 <=#Tp RxAbortSyncb1;
end
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
RxAbortLatched <=#Tp 1'b0;
else
if(RxAbortSyncb2)
RxAbortLatched <=#Tp 1'b0;
else
if(RxAbort)
RxAbortLatched <=#Tp 1'b1;
end
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
LatchedRxLength[15:0] <=#Tp 16'h0;
else
if(LoadRxStatus)
LatchedRxLength[15:0] <=#Tp RxLength[15:0];
end
assign RxStatusIn = {ReceivedPauseFrm, AddressMiss, RxOverrun, InvalidSymbol, DribbleNibble, ReceivedPacketTooBig, ShortFrame, LatchedCrcError, RxLateCollision};
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
RxStatusInLatched <=#Tp 'h0;
else
if(LoadRxStatus)
RxStatusInLatched <=#Tp RxStatusIn;
end
// Rx overrun
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
RxOverrun <=#Tp 1'b0;
else
if(RxStatusWrite)
RxOverrun <=#Tp 1'b0;
else
if(RxBufferFull & WriteRxDataToFifo_wb)
RxOverrun <=#Tp 1'b1;
end
wire TxError;
assign TxError = TxUnderRun | RetryLimit | LateCollLatched | CarrierSenseLost;
wire RxError;
// ShortFrame (RxStatusInLatched[2]) can not set an error because short frames
// are aborted when signal r_RecSmall is set to 0 in MODER register.
// AddressMiss is identifying that a frame was received because of the promiscous
// mode and is not an error
assign RxError = (|RxStatusInLatched[6:3]) | (|RxStatusInLatched[1:0]);
reg RxStatusWriteLatched;
reg RxStatusWriteLatched_sync1;
reg RxStatusWriteLatched_sync2;
reg RxStatusWriteLatched_syncb1;
reg RxStatusWriteLatched_syncb2;
// Latching and synchronizing RxStatusWrite signal. This signal is used for clearing the ReceivedPauseFrm signal
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
RxStatusWriteLatched <=#Tp 1'b0;
else
if(RxStatusWriteLatched_syncb2)
RxStatusWriteLatched <=#Tp 1'b0;
else
if(RxStatusWrite)
RxStatusWriteLatched <=#Tp 1'b1;
end
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
begin
RxStatusWriteLatched_sync1 <=#Tp 1'b0;
RxStatusWriteLatched_sync2 <=#Tp 1'b0;
end
else
begin
RxStatusWriteLatched_sync1 <=#Tp RxStatusWriteLatched;
RxStatusWriteLatched_sync2 <=#Tp RxStatusWriteLatched_sync1;
end
end
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
begin
RxStatusWriteLatched_syncb1 <=#Tp 1'b0;
RxStatusWriteLatched_syncb2 <=#Tp 1'b0;
end
else
begin
RxStatusWriteLatched_syncb1 <=#Tp RxStatusWriteLatched_sync2;
RxStatusWriteLatched_syncb2 <=#Tp RxStatusWriteLatched_syncb1;
end
end
// Tx Done Interrupt
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxB_IRQ <=#Tp 1'b0;
else
if(TxStatusWrite & TxIRQEn)
TxB_IRQ <=#Tp ~TxError;
else
TxB_IRQ <=#Tp 1'b0;
end
// Tx Error Interrupt
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
TxE_IRQ <=#Tp 1'b0;
else
if(TxStatusWrite & TxIRQEn)
TxE_IRQ <=#Tp TxError;
else
TxE_IRQ <=#Tp 1'b0;
end
// Rx Done Interrupt
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
RxB_IRQ <=#Tp 1'b0;
else
if(RxStatusWrite & RxIRQEn & ReceivedPacketGood & (~ReceivedPauseFrm | ReceivedPauseFrm & r_PassAll & (~r_RxFlow)))
RxB_IRQ <=#Tp (~RxError);
else
RxB_IRQ <=#Tp 1'b0;
end
// Rx Error Interrupt
always @ (posedge WB_CLK_I or posedge Reset)
begin
if(Reset)
RxE_IRQ <=#Tp 1'b0;
else
if(RxStatusWrite & RxIRQEn & (~ReceivedPauseFrm | ReceivedPauseFrm & r_PassAll & (~r_RxFlow)))
RxE_IRQ <=#Tp RxError;
else
RxE_IRQ <=#Tp 1'b0;
end
// Busy Interrupt
reg Busy_IRQ_rck;
reg Busy_IRQ_sync1;
reg Busy_IRQ_sync2;
reg Busy_IRQ_sync3;
reg Busy_IRQ_syncb1;
reg Busy_IRQ_syncb2;
always @ (posedge MRxClk or posedge Reset)
begin
if(Reset)
Busy_IRQ_rck <=#Tp 1'b0;
else
if(RxValid & RxStartFrm & ~RxReady)
Busy_IRQ_rck <=#Tp 1'b1;
else
if(Busy_IRQ_syncb2)
Busy_IRQ_rck <=#Tp 1'b0;
end
always @ (posedge WB_CLK_I)
begin
Busy_IRQ_sync1 <=#Tp Busy_IRQ_rck;
Busy_IRQ_sync2 <=#Tp Busy_IRQ_sync1;
Busy_IRQ_sync3 <=#Tp Busy_IRQ_sync2;
end
always @ (posedge MRxClk)
begin
Busy_IRQ_syncb1 <=#Tp Busy_IRQ_sync2;
Busy_IRQ_syncb2 <=#Tp Busy_IRQ_syncb1;
end
assign Busy_IRQ = Busy_IRQ_sync2 & ~Busy_IRQ_sync3;
endmodule
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