Subversion Repositories sdhc-sc-core

//

// file: SdCardModel.sv

// author: Rainer Kastl

//

// Models a SDCard for verification

//

const logic cActivated = 1;

const logic cInactivated = 0;

`define cSDArgWith 32

typedef logic[`cSDArgWith-1:0] SDCommandArg;

typedef logic[6:0] aCrc;

typedef enum {

         cSdCmdGoIdleState = 0,

         cSdCmdAllSendCID = 2,

         cSdCmdSendRelAdr = 3,

         cSdCmdSetDSR = 4, // [31:16] DSR

         cSdCmdSelCard = 7, // [31:16] RCA

         cSdCmdSendIfCond = 8, // [31:12] reserved, [11:8] supply voltage, [7:0] check pattern

         cSdCmdSendCSD = 9, // [31:16] RCA

         cSdCmdSendCID = 10, // [31:16] RCA

         cSdCmdStopTrans = 12,

         cSdCmdSendStatus = 13 // [31:16] RCA

} SDCommandId;

typedef enum {

        idle

} SDCardState;

class SDCommandToken;

        logic startbit;

        logic transbit;

        rand logic[5:0] id;

        rand SDCommandArg arg;

        aCrc crc7;

        logic endbit;

        function void display();

                $display("Startbit: %b", startbit);

                $display("Transbit: %b", transbit);

                $display("ID: %b", id);

                $display("Arg: %h", arg);

                $display("CRC: %b", crc7);

                $display("Endbit: %b" , endbit);

        endfunction

        function void checkStartEnd();

                assert(startbit == 0);

                assert(endbit == 1);

        endfunction

        function void checkFromHost();

                checkStartEnd();

                checkCrc();

                assert(transbit == 1);

        endfunction

        function void checkCrc();

                assert(crc7 == calcCrcOfToken());

        endfunction

        function automatic aCrc calcCrcOfToken();

                logic[39:0] temp;

                aCrc crc = 0;

                temp[39] = startbit;

                temp[38] = transbit;

                temp[37:32] = id;

                temp[31:0] = arg;

                for(int i = 39; i >= 0; i--) begin

                        if (((crc[6] & 1)) != temp[i])

                                 crc = (crc << 1) ^ 'b10001001;

                        else

                                 crc <<= 1;

                end

                return crc;

        endfunction

        function automatic bit equals(SDCommandToken rhs);

                if(id == rhs.id && arg == rhs.arg) begin

                        return 1;

                end

                return 0;

        endfunction

endclass

class SDCommandResponse;

        protected logic startbit;

        protected logic transbit;

        protected logic[5:0] id;

        protected SDCommandArg arg;

        protected aCrc crc;

        protected logic endbit;

        function automatic void calcCrc();

                logic[39:0] temp;

                crc = 0;

                temp[39] = startbit;

                temp[38] = transbit;

                temp[37:32] = id;

                temp[31:0] = arg;

                for(int i = 39; i >= 0; i--) begin

                        if (((crc[6] & 1)) != temp[i])

                                 crc = (crc << 1) ^ 'b10001001;

                        else

                                 crc <<= 1;

                end

        endfunction

        task automatic send(virtual ISdCmd.Card ICmd);

                calcCrc();

                @ICmd.cb;

                ICmd.cb.Cmd <= startbit;

                @ICmd.cb;

                ICmd.cb.Cmd <= transbit;

                for(int i = 5; i >= 0; i--) begin

                        @ICmd.cb;

                        ICmd.cb.Cmd <= id[i];

                end

                for (int i = 31; i>= 0; i--) begin

                        @ICmd.cb;

                        ICmd.cb.Cmd <= arg[i];

                end

                for (int i = 6; i >= 0; i--) begin

                        @ICmd.cb;

                        ICmd.cb.Cmd <= crc[i];

                end

                @ICmd.cb;

                ICmd.cb.Cmd <= endbit;

                @ICmd.cb;

                ICmd.cb.Cmd <= 'z;

        endtask

endclass

class SDCommandR7 extends SDCommandResponse;

        function new(SDCommandArg arg);

                startbit = 0;

                transbit = 0;

                id = cSdCmdSendIfCond;

                this.arg = arg;

                endbit = 1;

        endfunction

endclass

class SDCard;

        local virtual ISdCmd.Card ICmd;

        local SDCardState state;

        local SDCommandToken recvcmd;

        local event CmdReceived, InitDone;

        function new(virtual ISdCmd CmdInterface, event CmdReceived, event InitDone);

                ICmd = CmdInterface;

                state = idle;

                this.CmdReceived = CmdReceived;

                this.InitDone = InitDone;

        endfunction

        task reset();

                state = idle;

        endtask

        // Receive a command token and handle it

        task recv();

                recvcmd = new();

                ICmd.cb.Cmd <= 'z;

                wait(ICmd.cb.Cmd == 0);

                // Startbit

                recvcmd.startbit = ICmd.cb.Cmd;

                @ICmd.cb;

                // Transbit

                recvcmd.transbit = ICmd.cb.Cmd;

                // CmdID

                for (int i = 5; i >= 0; i--) begin

                        @ICmd.cb;

                        recvcmd.id[i] = ICmd.cb.Cmd;

                end

                // Arg

                for (int i = 31; i >= 0; i--) begin

                        @ICmd.cb;

                        recvcmd.arg[i] = ICmd.cb.Cmd;

                end

                // CRC

                for (int i = 6; i >= 0; i--) begin

                        @ICmd.cb;

                        recvcmd.crc7[i] = ICmd.cb.Cmd;

                end

                // Endbit

                @ICmd.cb;

                recvcmd.endbit = ICmd.cb.Cmd;

                recvcmd.checkFromHost();

                -> CmdReceived;

        endtask

        task automatic init();

                SDCommandR7 voltageresponse;

                SDCommandResponse response;

                // expect CMD0 so that state is clear

                recv();

                assert(recvcmd.id == cSdCmdGoIdleState);

                // expect CMD8: voltage and SD 2.00 compatible

                recv();

                assert(recvcmd.id == cSdCmdSendIfCond);

                assert(recvcmd.arg[12:8] == 'b0001); // Standard voltage

                // respond with R7: we are SD 2.00 compatible and compatible to the

                // voltage

                voltageresponse = new(recvcmd.arg);

                response = voltageresponse;

                response.send(ICmd);

                -> InitDone;

        endtask

        function automatic SDCommandToken getCmd();

                return recvcmd;

        endfunction

        task recvCmd(input SDCommandToken cmd, output SDCommandResponse response);

                case (cmd.id)

                        cSdCmdGoIdleState: reset();

                        default: $display("SDCard: CmdId %d not implemented", cmd.id);

                endcase

        endtask

endclass