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

452 lines
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Verilog

//////////////////////////////////////////////////////////////////////
//// ////
//// eth_miim.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_miim.v,v $
// Revision 1.7 2005/03/21 20:07:18 igorm
// Some small fixes + some troubles fixed.
//
// Revision 1.6 2005/02/21 12:48:07 igorm
// Warning fixes.
//
// Revision 1.5 2003/05/16 10:08:27 mohor
// Busy was set 2 cycles too late. Reported by Dennis Scott.
//
// Revision 1.4 2002/08/14 18:32:10 mohor
// - Busy signal was not set on time when scan status operation was performed
// and clock was divided with more than 2.
// - Nvalid remains valid two more clocks (was previously cleared too soon).
//
// 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 1.2 2001/08/02 09:25:31 mohor
// Unconnected signals are now connected.
//
// Revision 1.1 2001/07/30 21:23:42 mohor
// Directory structure changed. Files checked and joind together.
//
// Revision 1.3 2001/06/01 22:28:56 mohor
// This files (MIIM) are fully working. They were thoroughly tested. The testbench is not updated.
//
//
`include "timescale.v"
module eth_miim
(
Clk,
Reset,
Divider,
NoPre,
CtrlData,
Rgad,
Fiad,
WCtrlData,
RStat,
ScanStat,
Mdi,
Mdo,
MdoEn,
Mdc,
Busy,
Prsd,
LinkFail,
Nvalid,
WCtrlDataStart,
RStatStart,
UpdateMIIRX_DATAReg
);
input Clk; // Host Clock
input Reset; // General Reset
input [7:0] Divider; // Divider for the host clock
input [15:0] CtrlData; // Control Data (to be written to the PHY reg.)
input [4:0] Rgad; // Register Address (within the PHY)
input [4:0] Fiad; // PHY Address
input NoPre; // No Preamble (no 32-bit preamble)
input WCtrlData; // Write Control Data operation
input RStat; // Read Status operation
input ScanStat; // Scan Status operation
input Mdi; // MII Management Data In
output Mdc; // MII Management Data Clock
output Mdo; // MII Management Data Output
output MdoEn; // MII Management Data Output Enable
output Busy; // Busy Signal
output LinkFail; // Link Integrity Signal
output Nvalid; // Invalid Status (qualifier for the valid scan result)
output [15:0] Prsd; // Read Status Data (data read from the PHY)
output WCtrlDataStart; // This signals resets the WCTRLDATA bit in the MIIM Command register
output RStatStart; // This signal resets the RSTAT BIT in the MIIM Command register
output UpdateMIIRX_DATAReg;// Updates MII RX_DATA register with read data
parameter Tp = 1;
reg Nvalid;
reg EndBusy_d; // Pre-end Busy signal
reg EndBusy; // End Busy signal (stops the operation in progress)
reg WCtrlData_q1; // Write Control Data operation delayed 1 Clk cycle
reg WCtrlData_q2; // Write Control Data operation delayed 2 Clk cycles
reg WCtrlData_q3; // Write Control Data operation delayed 3 Clk cycles
reg WCtrlDataStart; // Start Write Control Data Command (positive edge detected)
reg WCtrlDataStart_q;
reg WCtrlDataStart_q1; // Start Write Control Data Command delayed 1 Mdc cycle
reg WCtrlDataStart_q2; // Start Write Control Data Command delayed 2 Mdc cycles
reg RStat_q1; // Read Status operation delayed 1 Clk cycle
reg RStat_q2; // Read Status operation delayed 2 Clk cycles
reg RStat_q3; // Read Status operation delayed 3 Clk cycles
reg RStatStart; // Start Read Status Command (positive edge detected)
reg RStatStart_q1; // Start Read Status Command delayed 1 Mdc cycle
reg RStatStart_q2; // Start Read Status Command delayed 2 Mdc cycles
reg ScanStat_q1; // Scan Status operation delayed 1 cycle
reg ScanStat_q2; // Scan Status operation delayed 2 cycles
reg SyncStatMdcEn; // Scan Status operation delayed at least cycles and synchronized to MdcEn
wire WriteDataOp; // Write Data Operation (positive edge detected)
wire ReadStatusOp; // Read Status Operation (positive edge detected)
wire ScanStatusOp; // Scan Status Operation (positive edge detected)
wire StartOp; // Start Operation (start of any of the preceding operations)
wire EndOp; // End of Operation
reg InProgress; // Operation in progress
reg InProgress_q1; // Operation in progress delayed 1 Mdc cycle
reg InProgress_q2; // Operation in progress delayed 2 Mdc cycles
reg InProgress_q3; // Operation in progress delayed 3 Mdc cycles
reg WriteOp; // Write Operation Latch (When asserted, write operation is in progress)
reg [6:0] BitCounter; // Bit Counter
wire [3:0] ByteSelect; // Byte Select defines which byte (preamble, data, operation, etc.) is loaded and shifted through the shift register.
wire MdcEn; // MII Management Data Clock Enable signal is asserted for one Clk period before Mdc rises.
wire ShiftedBit; // This bit is output of the shift register and is connected to the Mdo signal
wire MdcEn_n;
wire LatchByte1_d2;
wire LatchByte0_d2;
reg LatchByte1_d;
reg LatchByte0_d;
reg [1:0] LatchByte; // Latch Byte selects which part of Read Status Data is updated from the shift register
reg UpdateMIIRX_DATAReg;// Updates MII RX_DATA register with read data
// Generation of the EndBusy signal. It is used for ending the MII Management operation.
always @ (posedge Clk or posedge Reset)
begin
if(Reset)
begin
EndBusy_d <= #Tp 1'b0;
EndBusy <= #Tp 1'b0;
end
else
begin
EndBusy_d <= #Tp ~InProgress_q2 & InProgress_q3;
EndBusy <= #Tp EndBusy_d;
end
end
// Update MII RX_DATA register
always @ (posedge Clk or posedge Reset)
begin
if(Reset)
UpdateMIIRX_DATAReg <= #Tp 0;
else
if(EndBusy & ~WCtrlDataStart_q)
UpdateMIIRX_DATAReg <= #Tp 1;
else
UpdateMIIRX_DATAReg <= #Tp 0;
end
// Generation of the delayed signals used for positive edge triggering.
always @ (posedge Clk or posedge Reset)
begin
if(Reset)
begin
WCtrlData_q1 <= #Tp 1'b0;
WCtrlData_q2 <= #Tp 1'b0;
WCtrlData_q3 <= #Tp 1'b0;
RStat_q1 <= #Tp 1'b0;
RStat_q2 <= #Tp 1'b0;
RStat_q3 <= #Tp 1'b0;
ScanStat_q1 <= #Tp 1'b0;
ScanStat_q2 <= #Tp 1'b0;
SyncStatMdcEn <= #Tp 1'b0;
end
else
begin
WCtrlData_q1 <= #Tp WCtrlData;
WCtrlData_q2 <= #Tp WCtrlData_q1;
WCtrlData_q3 <= #Tp WCtrlData_q2;
RStat_q1 <= #Tp RStat;
RStat_q2 <= #Tp RStat_q1;
RStat_q3 <= #Tp RStat_q2;
ScanStat_q1 <= #Tp ScanStat;
ScanStat_q2 <= #Tp ScanStat_q1;
if(MdcEn)
SyncStatMdcEn <= #Tp ScanStat_q2;
end
end
// Generation of the Start Commands (Write Control Data or Read Status)
always @ (posedge Clk or posedge Reset)
begin
if(Reset)
begin
WCtrlDataStart <= #Tp 1'b0;
WCtrlDataStart_q <= #Tp 1'b0;
RStatStart <= #Tp 1'b0;
end
else
begin
if(EndBusy)
begin
WCtrlDataStart <= #Tp 1'b0;
RStatStart <= #Tp 1'b0;
end
else
begin
if(WCtrlData_q2 & ~WCtrlData_q3)
WCtrlDataStart <= #Tp 1'b1;
if(RStat_q2 & ~RStat_q3)
RStatStart <= #Tp 1'b1;
WCtrlDataStart_q <= #Tp WCtrlDataStart;
end
end
end
// Generation of the Nvalid signal (indicates when the status is invalid)
always @ (posedge Clk or posedge Reset)
begin
if(Reset)
Nvalid <= #Tp 1'b0;
else
begin
if(~InProgress_q2 & InProgress_q3)
begin
Nvalid <= #Tp 1'b0;
end
else
begin
if(ScanStat_q2 & ~SyncStatMdcEn)
Nvalid <= #Tp 1'b1;
end
end
end
// Signals used for the generation of the Operation signals (positive edge)
always @ (posedge Clk or posedge Reset)
begin
if(Reset)
begin
WCtrlDataStart_q1 <= #Tp 1'b0;
WCtrlDataStart_q2 <= #Tp 1'b0;
RStatStart_q1 <= #Tp 1'b0;
RStatStart_q2 <= #Tp 1'b0;
InProgress_q1 <= #Tp 1'b0;
InProgress_q2 <= #Tp 1'b0;
InProgress_q3 <= #Tp 1'b0;
LatchByte0_d <= #Tp 1'b0;
LatchByte1_d <= #Tp 1'b0;
LatchByte <= #Tp 2'b00;
end
else
begin
if(MdcEn)
begin
WCtrlDataStart_q1 <= #Tp WCtrlDataStart;
WCtrlDataStart_q2 <= #Tp WCtrlDataStart_q1;
RStatStart_q1 <= #Tp RStatStart;
RStatStart_q2 <= #Tp RStatStart_q1;
LatchByte[0] <= #Tp LatchByte0_d;
LatchByte[1] <= #Tp LatchByte1_d;
LatchByte0_d <= #Tp LatchByte0_d2;
LatchByte1_d <= #Tp LatchByte1_d2;
InProgress_q1 <= #Tp InProgress;
InProgress_q2 <= #Tp InProgress_q1;
InProgress_q3 <= #Tp InProgress_q2;
end
end
end
// Generation of the Operation signals
assign WriteDataOp = WCtrlDataStart_q1 & ~WCtrlDataStart_q2;
assign ReadStatusOp = RStatStart_q1 & ~RStatStart_q2;
assign ScanStatusOp = SyncStatMdcEn & ~InProgress & ~InProgress_q1 & ~InProgress_q2;
assign StartOp = WriteDataOp | ReadStatusOp | ScanStatusOp;
// Busy
assign Busy = WCtrlData | WCtrlDataStart | RStat | RStatStart | SyncStatMdcEn | EndBusy | InProgress | InProgress_q3 | Nvalid;
// Generation of the InProgress signal (indicates when an operation is in progress)
// Generation of the WriteOp signal (indicates when a write is in progress)
always @ (posedge Clk or posedge Reset)
begin
if(Reset)
begin
InProgress <= #Tp 1'b0;
WriteOp <= #Tp 1'b0;
end
else
begin
if(MdcEn)
begin
if(StartOp)
begin
if(~InProgress)
WriteOp <= #Tp WriteDataOp;
InProgress <= #Tp 1'b1;
end
else
begin
if(EndOp)
begin
InProgress <= #Tp 1'b0;
WriteOp <= #Tp 1'b0;
end
end
end
end
end
// Bit Counter counts from 0 to 63 (from 32 to 63 when NoPre is asserted)
always @ (posedge Clk or posedge Reset)
begin
if(Reset)
BitCounter[6:0] <= #Tp 7'h0;
else
begin
if(MdcEn)
begin
if(InProgress)
begin
if(NoPre & ( BitCounter == 7'h0 ))
BitCounter[6:0] <= #Tp 7'h21;
else
BitCounter[6:0] <= #Tp BitCounter[6:0] + 1'b1;
end
else
BitCounter[6:0] <= #Tp 7'h0;
end
end
end
// Operation ends when the Bit Counter reaches 63
assign EndOp = BitCounter==63;
assign ByteSelect[0] = InProgress & ((NoPre & (BitCounter == 7'h0)) | (~NoPre & (BitCounter == 7'h20)));
assign ByteSelect[1] = InProgress & (BitCounter == 7'h28);
assign ByteSelect[2] = InProgress & WriteOp & (BitCounter == 7'h30);
assign ByteSelect[3] = InProgress & WriteOp & (BitCounter == 7'h38);
// Latch Byte selects which part of Read Status Data is updated from the shift register
assign LatchByte1_d2 = InProgress & ~WriteOp & BitCounter == 7'h37;
assign LatchByte0_d2 = InProgress & ~WriteOp & BitCounter == 7'h3F;
// Connecting the Clock Generator Module
eth_clockgen clkgen(.Clk(Clk), .Reset(Reset), .Divider(Divider[7:0]), .MdcEn(MdcEn), .MdcEn_n(MdcEn_n), .Mdc(Mdc)
);
// Connecting the Shift Register Module
eth_shiftreg shftrg(.Clk(Clk), .Reset(Reset), .MdcEn_n(MdcEn_n), .Mdi(Mdi), .Fiad(Fiad), .Rgad(Rgad),
.CtrlData(CtrlData), .WriteOp(WriteOp), .ByteSelect(ByteSelect), .LatchByte(LatchByte),
.ShiftedBit(ShiftedBit), .Prsd(Prsd), .LinkFail(LinkFail)
);
// Connecting the Output Control Module
eth_outputcontrol outctrl(.Clk(Clk), .Reset(Reset), .MdcEn_n(MdcEn_n), .InProgress(InProgress),
.ShiftedBit(ShiftedBit), .BitCounter(BitCounter), .WriteOp(WriteOp), .NoPre(NoPre),
.Mdo(Mdo), .MdoEn(MdoEn)
);
endmodule