Subversion Repositories iso7816_3_master

`timescale 1ns / 1ps

//////////////////////////////////////////////////////////////////////////////////

// Company: 

// Engineer: Sebastien Riou

// 

// Create Date:    23:57:02 08/31/2010 

// Design Name: 

// Module Name:    Uart 

// Project Name: 

// Target Devices: 

// Tool versions: 

// Description: Half duplex UART with 1 byte buffer

//

// Dependencies: 

//

// Revision: 

// Revision 0.01 - File Created

// Additional Comments: 

//

//////////////////////////////////////////////////////////////////////////////////

module BasicHalfDuplexUart(

    output [7:0] rxData,

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

    output dataOutReadyFlag,    //new data available

    output frameErrorFlag,              //bad parity or bad stop bits

    output txRun,                                       //tx is started

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

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

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

    output txFull,

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

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

         output serialOut,

         output comClk,

    input [DIVIDER_WIDTH-1:0] clkPerCycle,

         input [7:0] txData,

         input [CLOCK_PER_BIT_WIDTH-1:0] clocksPerBit,

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

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

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

         input startTx,

         input ackFlags,

         input clk,

    input nReset

    );

//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;

//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)

                );

*/

// Instantiate the module

RxCoreSelfContained #(

                .DIVIDER_WIDTH(DIVIDER_WIDTH),

                .PARITY_POLARITY(PARITY_POLARITY))

        rxCore (

    .dataOut(rxData),

    .overrunErrorFlag(overrunErrorFlag),

    .dataOutReadyFlag(dataOutReadyFlag),

    .frameErrorFlag(frameErrorFlag),

    .endOfRx(endOfRx),

    .run(rxRun),

    .startBit(rxStartBit),

         .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))

        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