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repo2/common/components/usbhostslave/trunk/RTL/hostController/softransmit.v

264 markw
// File : ../RTL/hostController/softransmit.v
// Generated : 11/10/06 05:37:21
// From : ../RTL/hostController/softransmit.asf
// By : FSM2VHDL ver. 5.0.0.9

//////////////////////////////////////////////////////////////////////
//// ////
//// softransmit
//// ////
//// This file is part of the usbhostslave opencores effort.
//// http://www.opencores.org/cores/usbhostslave/ ////
//// ////
//// Module Description: ////
////
//// ////
//// To Do: ////
////
//// ////
//// Author(s): ////
//// - Steve Fielding, sfielding@base2designs.com ////
//// ////
//////////////////////////////////////////////////////////////////////
//// ////
//// Copyright (C) 2004 Steve Fielding and OPENCORES.ORG ////
//// ////
//// 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 ////
//// ////
//////////////////////////////////////////////////////////////////////
//
`include "timescale.v"
`include "usbHostControl_h.v"


module SOFTransmit (SOFEnable, SOFSent, SOFSyncEn, SOFTimerClr, SOFTimer, clk, rst, sendPacketArbiterGnt, sendPacketArbiterReq, sendPacketRdy, sendPacketWEn, fullSpeedRate);
input SOFEnable; // After host software asserts SOFEnable, must wait TBD time before asserting SOFSyncEn
input SOFSyncEn;
input [15:0] SOFTimer;
input clk;
input rst;
input sendPacketArbiterGnt;
input sendPacketRdy;
output SOFSent; // single cycle pulse
output SOFTimerClr; // Single cycle pulse
output sendPacketArbiterReq;
output sendPacketWEn;
input fullSpeedRate;

wire SOFEnable;
reg SOFSent, next_SOFSent;
wire SOFSyncEn;
reg SOFTimerClr, next_SOFTimerClr;
wire [15:0] SOFTimer;
wire clk;
wire rst;
wire sendPacketArbiterGnt;
reg sendPacketArbiterReq, next_sendPacketArbiterReq;
wire sendPacketRdy;
reg sendPacketWEn, next_sendPacketWEn;
reg [15:0] SOFNearTime;

// diagram signals declarations
reg [7:0]i, next_i;

// BINARY ENCODED state machine: SOFTx
// State codes definitions:
`define START_STX 3'b000
`define WAIT_SOF_NEAR 3'b001
`define WAIT_SP_GNT 3'b010
`define WAIT_SOF_NOW 3'b011
`define SOF_FIN 3'b100
`define DLY_SOF_CHK1 3'b101
`define DLY_SOF_CHK2 3'b110

reg [2:0] CurrState_SOFTx;
reg [2:0] NextState_SOFTx;


//--------------------------------------------------------------------
// Machine: SOFTx
//--------------------------------------------------------------------
//----------------------------------
// Next State Logic (combinatorial)
//----------------------------------
always @ (i or SOFTimer or SOFSyncEn or SOFEnable or sendPacketArbiterGnt or sendPacketRdy or sendPacketArbiterReq or sendPacketWEn or SOFTimerClr or SOFSent or CurrState_SOFTx)
begin : SOFTx_NextState
NextState_SOFTx <= CurrState_SOFTx;
// Set default values for outputs and signals
next_sendPacketArbiterReq <= sendPacketArbiterReq;
next_sendPacketWEn <= sendPacketWEn;
next_SOFTimerClr <= SOFTimerClr;
next_SOFSent <= SOFSent;
next_i <= i;
case (CurrState_SOFTx)
`START_STX:
NextState_SOFTx <= `WAIT_SOF_NEAR;
`WAIT_SOF_NEAR:
if (SOFTimer >= SOFNearTime ||
(SOFSyncEn == 1'b1 &&
SOFEnable == 1'b1))
begin
NextState_SOFTx <= `WAIT_SP_GNT;
next_sendPacketArbiterReq <= 1'b1;
end
`WAIT_SP_GNT:
if (sendPacketArbiterGnt == 1'b1 && sendPacketRdy == 1'b1)
NextState_SOFTx <= `WAIT_SOF_NOW;
`WAIT_SOF_NOW:
if (SOFTimer >= `SOF_TX_TIME)
begin
NextState_SOFTx <= `SOF_FIN;
next_sendPacketWEn <= 1'b1;
next_SOFTimerClr <= 1'b1;
next_SOFSent <= 1'b1;
end
else if (SOFEnable == 1'b0)
begin
NextState_SOFTx <= `SOF_FIN;
next_SOFTimerClr <= 1'b1;
end
`SOF_FIN:
begin
next_sendPacketWEn <= 1'b0;
next_SOFTimerClr <= 1'b0;
next_SOFSent <= 1'b0;
if (sendPacketRdy == 1'b1)
begin
NextState_SOFTx <= `DLY_SOF_CHK1;
next_i <= 8'h00;
end
end
`DLY_SOF_CHK1:
begin
next_i <= i + 1'b1;
if (i==8'hff)
begin
NextState_SOFTx <= `DLY_SOF_CHK2;
next_sendPacketArbiterReq <= 1'b0;
next_i <= 8'h00;
end
end
`DLY_SOF_CHK2:
begin
next_i <= i + 1'b1;
if (i==8'hff)
NextState_SOFTx <= `WAIT_SOF_NEAR;
end
endcase
end

//----------------------------------
// Current State Logic (sequential)
//----------------------------------
always @ (posedge clk)
begin : SOFTx_CurrentState
if (rst)
CurrState_SOFTx <= `START_STX;
else
CurrState_SOFTx <= NextState_SOFTx;
end

//----------------------------------
// Registered outputs logic
//----------------------------------
always @ (posedge clk)
begin : SOFTx_RegOutput
if (rst)
begin
i <= 8'h00;
SOFSent <= 1'b0;
SOFTimerClr <= 1'b0;
sendPacketArbiterReq <= 1'b0;
sendPacketWEn <= 1'b0;
SOFNearTime <= 16'h0000;
end
else
begin
i <= next_i;
SOFSent <= next_SOFSent;
SOFTimerClr <= next_SOFTimerClr;
sendPacketArbiterReq <= next_sendPacketArbiterReq;
sendPacketWEn <= next_sendPacketWEn;
if (fullSpeedRate == 1'b1)
SOFNearTime <= `SOF_TX_TIME - `SOF_TX_MARGIN;
else
SOFNearTime <= `SOF_TX_TIME - `SOF_TX_MARGIN_LOW_SPEED;
end
end

endmodule