Subversion Repositories iso7816_3_master

/*

Author: Sebastien Riou (acapola)

Creation date: 23:57:02 08/31/2010

$LastChangedDate: 2011-01-29 13:16:17 +0100 (Sat, 29 Jan 2011) $

$LastChangedBy: acapola $

$LastChangedRevision: 11 $

$HeadURL: file:///svn/iso7816_3_master/iso7816_3_master/trunk/sources/Uart.v $

This file is under the BSD licence:

Copyright (c) 2011, Sebastien Riou

All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

The names of contributors may not be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR

CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*/

`default_nettype none

`timescale 1ns / 1ps

/*

Half duplex UART with 1 byte buffer

*/

module BasicHalfDuplexUart

#(//parameters to override

        parameter DIVIDER_WIDTH = 1,

        parameter CLOCK_PER_BIT_WIDTH = 13,     //allow to support default speed of ISO7816

        //invert the polarity of the output or not

        parameter IN_POLARITY = 1'b0,

        parameter PARITY_POLARITY = 1'b1,

        //default conventions

        parameter START_BIT = 1'b0,

        parameter STOP_BIT1 = 1'b1,

        parameter STOP_BIT2 = 1'b1

)

(

    output wire [7:0] rxData,

    output wire overrunErrorFlag,       //new data has been received before dataOut was read

    output wire dataOutReadyFlag,       //new data available

    output wire frameErrorFlag,         //bad parity or bad stop bits

    output wire txRun,                                  //tx is started

    output wire endOfRx,           //one cycle pulse: 1 during last cycle of last stop bit of rx

    output wire rxRun,                                  //rx is definitely started, one of the three flag will be set

    output wire rxStartBit,                     //rx is started, but we don't know yet if real rx or just a glitch

    output wire txFull,

    output wire isTx,              //1 only when tx is ongoing. Indicates the direction of the com line.

         input wire serialIn,                           //signals to merged into a inout signal according to "isTx"

         output wire serialOut,

         output wire comClk,

    input wire [DIVIDER_WIDTH-1:0] clkPerCycle,

         input wire [7:0] txData,

         input wire [CLOCK_PER_BIT_WIDTH-1:0] clocksPerBit,

         input wire stopBit2,//0: 1 stop bit, 1: 2 stop bits

         input wire oddParity, //if 1, parity bit is such that data+parity have an odd number of 1

    input wire msbFirst,  //if 1, bits order is: startBit, b7, b6, b5...b0, parity

         input wire startTx,

         input wire ackFlags,

         input wire clk,

    input wire nReset

    );

//constant definition for states

localparam IDLE_STATE =         3'b000;

localparam RX_STATE =   3'b001;

localparam TX_STATE =   3'b011;

wire rxSerialIn = isTx ? STOP_BIT1 : serialIn;

//wire serialOut;

wire loadDataIn;

wire txStopBits;

assign isTx = txRun & ~txStopBits;

//let this to top level to avoid inout signal

//assign serialLine = isTx ? serialOut : 1'bz;

assign loadDataIn = startTx & ~rxStartBit & (~rxRun | endOfRx);

/*//complicated approach... instead we can simply divide the clock at lower levels

wire useEarlyComClk = |clkPerCycle ? 1'b1:1'b0;

reg dividedClk;

wire earlyComClk;//earlier than comClk by 1 cycle of clk (use to make 1 cycle pulse signals)

always @(posedge clk)begin

        if(useEarlyComClk)

                dividedClk <= earlyComClk;

end

assign comClk=useEarlyComClk ? dividedClk : clk;//clock for communication

wire endOfRxComClk;//pulse of 1 cycle of comClk

assign endOfRx = useEarlyComClk ? endOfRxComClk & earlyComClk & ~comClk : endOfRxComClk;//pulse of 1 cycle of clk

ClkDivider #(.DIVIDER_WIDTH(DIVIDER_WIDTH))

        clkDivider(

                .nReset(nReset),

                .clk(clk),

                .divider(clkPerCycle),

                .dividedClk(earlyComClk)

                );

*/

wire stopBit;

// Instantiate the module

RxCoreSelfContained #(

                .DIVIDER_WIDTH(DIVIDER_WIDTH),

                .CLOCK_PER_BIT_WIDTH(CLOCK_PER_BIT_WIDTH)

                )

        rxCore (

    .dataOut(rxData),

    .overrunErrorFlag(overrunErrorFlag),

    .dataOutReadyFlag(dataOutReadyFlag),

    .frameErrorFlag(frameErrorFlag),

    .endOfRx(endOfRx),

    .run(rxRun),

    .startBit(rxStartBit),

         .stopBit(stopBit),

    .clkPerCycle(clkPerCycle),

    .clocksPerBit(clocksPerBit),

    .stopBit2(stopBit2),

    .oddParity(oddParity),

    .msbFirst(msbFirst),

         .ackFlags(ackFlags),

    .serialIn(rxSerialIn),

    .comClk(comClk),

    .clk(clk),

    .nReset(nReset)

    );

TxCore #(.DIVIDER_WIDTH(DIVIDER_WIDTH),

                        .CLOCK_PER_BIT_WIDTH(CLOCK_PER_BIT_WIDTH)

                )

        txCore (

        .serialOut(serialOut),

        .run(txRun),

        .full(txFull),

   .stopBits(txStopBits),

        .dataIn(txData),

        .clkPerCycle(clkPerCycle),

        .clocksPerBit(clocksPerBit),

        .stopBit2(stopBit2),

   .oddParity(oddParity),

   .msbFirst(msbFirst),

        .loadDataIn(loadDataIn),

        .comClk(comClk),

   .clk(clk),

   .nReset(nReset)

);

endmodule

`default_nettype wire