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[/] [usbhostslave/] [tags/] [rel_00_06_alpha/] [RTL/] [serialInterfaceEngine/] [processTxByte.v] - Rev 5
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////////////////////////////////////////////////////////////////////// //// //// //// processTxByte //// //// //// 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 //// //// //// ////////////////////////////////////////////////////////////////////// // // $Id: processTxByte.v,v 1.2 2004-12-18 14:36:16 sfielding Exp $ // // CVS Revision History // // $Log: not supported by cvs2svn $ // `timescale 1ns / 1ps `include "usbSerialInterfaceEngine_h.v" `include "usbConstants_h.v" module processTxByte (clk, JBit, KBit, processTxByteRdy, processTxByteWEn, rst, TxByteCtrlIn, TxByteIn, USBWireCtrl, USBWireData, USBWireGnt, USBWireRdy, USBWireReq, USBWireWEn); input clk; input [1:0]JBit; input [1:0]KBit; input processTxByteWEn; input rst; input [7:0]TxByteCtrlIn; input [7:0]TxByteIn; input USBWireGnt; input USBWireRdy; output processTxByteRdy; output USBWireCtrl; output [1:0]USBWireData; output USBWireReq; output USBWireWEn; wire clk; wire [1:0]JBit; wire [1:0]KBit; reg processTxByteRdy, next_processTxByteRdy; wire processTxByteWEn; wire rst; wire [7:0]TxByteCtrlIn; wire [7:0]TxByteIn; reg USBWireCtrl, next_USBWireCtrl; reg [1:0]USBWireData, next_USBWireData; wire USBWireGnt; wire USBWireRdy; reg USBWireReq, next_USBWireReq; reg USBWireWEn, next_USBWireWEn; // diagram signals declarations reg [3:0]i, next_i; reg [7:0]TxByte, next_TxByte; reg [7:0]TxByteCtrl, next_TxByteCtrl; reg [1:0]TXLineState, next_TXLineState; reg [3:0]TXOneCount, next_TXOneCount; // BINARY ENCODED state machine: prcTxB // State codes definitions: `define START_PTBY 4'b0000 `define PTBY_WAIT_EN 4'b0001 `define SEND_BYTE_UPDATE_BYTE 4'b0010 `define SEND_BYTE_WAIT_RDY 4'b0011 `define SEND_BYTE_CHK 4'b0100 `define SEND_BYTE_BIT_STUFF 4'b0101 `define SEND_BYTE_WAIT_RDY2 4'b0110 `define SEND_BYTE_CHK_FIN 4'b0111 `define PTBY_WAIT_GNT 4'b1000 `define STOP_SND_SE0_2 4'b1001 `define STOP_SND_SE0_1 4'b1010 `define STOP_CHK 4'b1011 `define STOP_SND_J 4'b1100 `define STOP_SND_IDLE 4'b1101 `define STOP_FIN 4'b1110 reg [3:0]CurrState_prcTxB, NextState_prcTxB; // Machine: prcTxB // NextState logic (combinatorial) always @ (processTxByteWEn or TxByteIn or TxByteCtrlIn or i or TxByte or TXOneCount or KBit or JBit or USBWireRdy or TXLineState or USBWireGnt or TxByteCtrl or processTxByteRdy or USBWireData or USBWireCtrl or USBWireReq or USBWireWEn or CurrState_prcTxB) begin NextState_prcTxB <= CurrState_prcTxB; // Set default values for outputs and signals next_processTxByteRdy <= processTxByteRdy; next_USBWireData <= USBWireData; next_USBWireCtrl <= USBWireCtrl; next_USBWireReq <= USBWireReq; next_USBWireWEn <= USBWireWEn; next_i <= i; next_TxByte <= TxByte; next_TxByteCtrl <= TxByteCtrl; next_TXLineState <= TXLineState; next_TXOneCount <= TXOneCount; case (CurrState_prcTxB) // synopsys parallel_case full_case `START_PTBY: begin next_processTxByteRdy <= 1'b0; next_USBWireData <= 2'b00; next_USBWireCtrl <= `TRI_STATE; next_USBWireReq <= 1'b0; next_USBWireWEn <= 1'b0; next_i <= 4'h0; next_TxByte <= 8'h00; next_TxByteCtrl <= 8'h00; next_TXLineState <= 2'b0; next_TXOneCount <= 4'h0; NextState_prcTxB <= `PTBY_WAIT_EN; end `PTBY_WAIT_EN: begin next_processTxByteRdy <= 1'b1; if ((processTxByteWEn == 1'b1) && (TxByteCtrlIn == `DATA_START)) begin NextState_prcTxB <= `PTBY_WAIT_GNT; next_processTxByteRdy <= 1'b0; next_TxByte <= TxByteIn; next_TxByteCtrl <= TxByteCtrlIn; next_TXOneCount <= 1; next_TXLineState <= JBit; next_USBWireReq <= 1'b1; end else if (processTxByteWEn == 1'b1) begin NextState_prcTxB <= `SEND_BYTE_UPDATE_BYTE; next_processTxByteRdy <= 1'b0; next_TxByte <= TxByteIn; next_TxByteCtrl <= TxByteCtrlIn; next_i <= 4'h0; end end `PTBY_WAIT_GNT: begin if (USBWireGnt == 1'b1) begin NextState_prcTxB <= `SEND_BYTE_UPDATE_BYTE; next_i <= 4'h0; end end `SEND_BYTE_UPDATE_BYTE: begin next_i <= i + 1'b1; next_TxByte <= {1'b0, TxByte[7:1] }; if (TxByte[0] == 1'b1) //If this bit is 1, then next_TXOneCount <= TXOneCount + 1'b1; //increment 'TXOneCount' else //else this is a zero bit begin next_TXOneCount <= 4'h1; //reset 'TXOneCount' if (TXLineState == JBit) next_TXLineState <= KBit; //toggle the line state else next_TXLineState <= JBit; end NextState_prcTxB <= `SEND_BYTE_WAIT_RDY; end `SEND_BYTE_WAIT_RDY: begin if (USBWireRdy == 1'b1) begin NextState_prcTxB <= `SEND_BYTE_CHK; next_USBWireWEn <= 1'b1; next_USBWireData <= TXLineState; next_USBWireCtrl <= `DRIVE; end end `SEND_BYTE_CHK: begin next_USBWireWEn <= 1'b0; if (TXOneCount == 4'h6) begin NextState_prcTxB <= `SEND_BYTE_BIT_STUFF; end else if (i != 4'h8) begin NextState_prcTxB <= `SEND_BYTE_UPDATE_BYTE; end else begin NextState_prcTxB <= `STOP_CHK; end end `SEND_BYTE_BIT_STUFF: begin next_TXOneCount <= 4'h1; //reset 'TXOneCount' if (TXLineState == JBit) next_TXLineState <= KBit; //toggle the line state else next_TXLineState <= JBit; NextState_prcTxB <= `SEND_BYTE_WAIT_RDY2; end `SEND_BYTE_WAIT_RDY2: begin if (USBWireRdy == 1'b1) begin NextState_prcTxB <= `SEND_BYTE_CHK_FIN; next_USBWireWEn <= 1'b1; next_USBWireData <= TXLineState; next_USBWireCtrl <= `DRIVE; end end `SEND_BYTE_CHK_FIN: begin next_USBWireWEn <= 1'b0; if (i == 4'h8) begin NextState_prcTxB <= `STOP_CHK; end else begin NextState_prcTxB <= `SEND_BYTE_UPDATE_BYTE; end end `STOP_SND_SE0_2: begin next_USBWireWEn <= 1'b0; if (USBWireRdy == 1'b1) begin NextState_prcTxB <= `STOP_SND_J; next_USBWireWEn <= 1'b1; next_USBWireData <= `SE0; next_USBWireCtrl <= `DRIVE; end end `STOP_SND_SE0_1: begin if (USBWireRdy == 1'b1) begin NextState_prcTxB <= `STOP_SND_SE0_2; next_USBWireWEn <= 1'b1; next_USBWireData <= `SE0; next_USBWireCtrl <= `DRIVE; end end `STOP_CHK: begin if (TxByteCtrl == `DATA_STOP) begin NextState_prcTxB <= `STOP_SND_SE0_1; end else begin NextState_prcTxB <= `PTBY_WAIT_EN; end end `STOP_SND_J: begin next_USBWireWEn <= 1'b0; if (USBWireRdy == 1'b1) begin NextState_prcTxB <= `STOP_SND_IDLE; next_USBWireWEn <= 1'b1; next_USBWireData <= JBit; next_USBWireCtrl <= `DRIVE; end end `STOP_SND_IDLE: begin next_USBWireWEn <= 1'b0; if (USBWireRdy == 1'b1) begin NextState_prcTxB <= `STOP_FIN; next_USBWireWEn <= 1'b1; next_USBWireData <= JBit; next_USBWireCtrl <= `TRI_STATE; end end `STOP_FIN: begin next_USBWireWEn <= 1'b0; next_USBWireReq <= 1'b0; //release the wire NextState_prcTxB <= `PTBY_WAIT_EN; end endcase end // Current State Logic (sequential) always @ (posedge clk) begin if (rst) CurrState_prcTxB <= `START_PTBY; else CurrState_prcTxB <= NextState_prcTxB; end // Registered outputs logic always @ (posedge clk) begin if (rst) begin processTxByteRdy <= 1'b0; USBWireData <= 2'b00; USBWireCtrl <= `TRI_STATE; USBWireReq <= 1'b0; USBWireWEn <= 1'b0; i <= 4'h0; TxByte <= 8'h00; TxByteCtrl <= 8'h00; TXLineState <= 2'b0; TXOneCount <= 4'h0; end else begin processTxByteRdy <= next_processTxByteRdy; USBWireData <= next_USBWireData; USBWireCtrl <= next_USBWireCtrl; USBWireReq <= next_USBWireReq; USBWireWEn <= next_USBWireWEn; i <= next_i; TxByte <= next_TxByte; TxByteCtrl <= next_TxByteCtrl; TXLineState <= next_TXLineState; TXOneCount <= next_TXOneCount; end end endmodule
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