testbench.vhd

在逻辑的系统仿真中使用的FLASH模型（AMD的Am29lv160d）

                    WAIT FOR 50 ns;
                ELSE
                    WAIT FOR 100 ns;
                END IF;

            WHEN bus_read  =>

                T_CENeg     <= '0' ;
                T_WENeg     <= '1'AFTER 10 ns;
                IF NOT disable  THEN
                    T_OENeg <= '0' AFTER 15 ns;
                ELSE
                    T_OENeg <= '1';
                END IF;

                IF NOT byte THEN
                    T_DQ(15 downto 8) <= (OTHERS => 'Z');
                END IF;
                T_DQ(7 downto 0)      <= (OTHERS => 'Z');

                WAIT FOR 100 ns;

                -- T_OENeg <= '1' ; -----------

        END CASE;


    END PROCEDURE;


   ---------------------------------------------------------------------------
    --procedure to decode commands into specific bus command sequence
    ---------------------------------------------------------------------------
    PROCEDURE cmd_dc
        (   command  :   IN  cmd_rec   )
    IS
        VARIABLE    D_hi    : NATURAL ;--RANGE 0 to MaxData;
        VARIABLE    D_lo    : NATURAL RANGE 0 to MaxData;
        VARIABLE    Addr    : NATURAL RANGE 0 to SecSize  :=0;
        VARIABLE    Addrfix : NATURAL RANGE 0 to SecSize/2:=0;
        VARIABLE    Sect    : INTEGER RANGE -1 to SecNum  :=0;
        VARIABLE    slv_1, slv_2 : std_logic_vector(7 downto 0);
        VARIABLE    byte    : boolean;
        VARIABLE    i       : NATURAL;
    BEGIN
        CASE command.cmd IS
            WHEN    idle        =>
                bus_cycle(bus_cmd => bus_idle,
                          byte    => command.byte,
                          disable => command.aux=disable);

            WHEN    h_reset     =>
                bus_cycle(bus_cmd => bus_reset,
                          byte    => command.byte,
                          tm      => command.wtime);

            WHEN    rd        =>
                bus_cycle(bus_cmd => bus_enable,
                          byte    => command.byte,
                          data    => -1,
                          sector  => command.sect,
                          address => command.addr,
                          tm      => 90 ns);

                bus_cycle(bus_cmd => bus_read,
                          byte    => command.byte,
                          data    => -1,
                          dataHi  => -1,
                          sector  => command.sect,
                          address => command.addr,
                          disable => command.aux=disable);

                bus_cycle(bus_cmd => bus_output_disable,
                          byte    => command.byte);

            WHEN    rd_page     =>
                bus_cycle(bus_cmd => bus_enable,
                          byte    => command.byte,
                          data    => -1,
                          sector  => 0,
                          address => 0,
                          tm      => 90 ns);

                Addr :=  command.addr;
                Sect :=  command.sect;
                byte :=  command.byte;
                ---- 08July----
                WAIT FOR 10 ns;
                --------------
                i := 0;
                WHILE i < command.d_hi LOOP

                    IF command.wtime > 0 ns THEN

                        bus_cycle(bus_cmd => bus_output_disable,  ----
                                  byte    => byte);       ----

                        --byte toggle mode
                        bus_cycle(bus_cmd => bus_enable,
                                  byte    => byte,
                                  data    => -1,
                                  sector  => -1,
                                  tm      => 10 ns);
                        byte := false;
                        bus_cycle(bus_cmd => bus_enable,
                                  byte    => byte,
                                  data    => -1,
                                  sector  => -1,
                                  tm      => 10 ns);
                        Addrfix := Addr /2;
                        IF Addr < SecSize THEN
                            Addr := Addr+1;
                        ELSE
                            Addr := 0;
                            IF Sect < SecNum THEN
                                Sect := Sect+1;
                            ELSE
                                REPORT "No more locations to read !!!"
                                SEVERITY warning;
                            END IF;
                        END IF;
                        --word read;
                        bus_cycle(bus_cmd => bus_read,
                                  byte    => byte,
                                  data    => -1,
                                  dataHi  => -1,
                                  sector  => Sect,
                                  address => Addrfix);

                        bus_cycle(bus_cmd => bus_output_disable,  ----
                                  byte    => byte);       ----

                        bus_cycle(bus_cmd => bus_enable,
                                  byte    => byte,
                                  data    => -1,
                                  sector  => -1,
                                  tm      => 10 ns);
                        byte := true;
                        bus_cycle(bus_cmd => bus_enable,
                                  byte    => byte,
                                  data    => -1,
                                  sector  => -1,
                                  tm      => 30 ns);

                        --first byte read
                        bus_cycle(bus_cmd => bus_read,
                                  byte    => byte,
                                  data    => -1,
                                  dataHi  => -1,
                                  sector  => Sect,
                                  address => Addr);

                        bus_cycle(bus_cmd => bus_output_disable,  ----
                                  byte    => byte);       ----

                        IF Addr < SecSize THEN
                            Addr := Addr+1;
                        ELSE
                            Addr := 0;
                            IF Sect < SecNum THEN
                                Sect := Sect+1;
                            ELSE
                                REPORT "No more locations to read !!!"
                                SEVERITY warning;
                            END IF;
                        END IF;
                        i := i +3;
                        wait for 10 ns; -------
                    ELSE
                        byte :=  command.byte;
                    END IF;
                    --second byte read in byte toggle mode
                    bus_cycle(bus_cmd => bus_read,
                              byte    => byte,
                              data    => -1,
                              dataHi  => -1,
                              sector  => Sect,
                              address => Addr);


                    IF Addr < SecSize THEN
                        Addr := Addr+1;
                    ELSE
                        Addr := 0;
                        IF Sect < SecNum THEN
                            Sect := Sect+1;
                        ELSE
                            REPORT "No more locations to read !!!"
                            SEVERITY warning;
                        END IF;
                    END IF;
                    i := i +1;
                    WAIT FOR 10 ns;
                END LOOP;
                bus_cycle(bus_cmd => bus_output_disable,
                          byte    => command.byte);



            WHEN    w_cycle     =>

                D_lo    :=  16#AA# ; --first command data
                Addr    :=  16#AAA#; --first command byte address
                D_hi    :=  16#55#;  --second command data
                Addrfix :=  16#555#; --second command byte address
                IF NOT command.byte THEN
                    --if word addressing
                    Addr    := 16#555#; --first command byte address
                    Addrfix := 16#2AA#; --second command byte address
                END IF;

                bus_cycle(bus_cmd => bus_write,
                         byte    => command.byte,
                         data    => D_lo,
                         dataHi  => 0,
                         sector  => 0,
                         address => Addr,
                         violate => command.aux=violate,
                         tm      => command.wtime);

                bus_cycle(bus_cmd => bus_standby,
                         byte    => command.byte);

                bus_cycle(bus_cmd => bus_write,
                         byte    => command.byte,
                         data    => D_hi,
                         dataHi  => 0,
                         sector  => 0,
                         address => Addrfix);

                bus_cycle(bus_cmd => bus_standby,
                         byte    => command.byte);


            WHEN    w_reset | w_prog | w_erase | w_unlock |
                    w_autoselect | w_enter_sec   =>
                Addr    :=  16#AAA#;
                IF NOT command.byte THEN
                    --if word addressing
                    Addr    := 16#555#; --first command byte address
                END IF;

                CASE  command.cmd IS
                    WHEN w_reset =>
                        d_lo := 16#F0#;
                    WHEN w_prog =>
                        d_lo := 16#A0#;
                    WHEN w_erase =>
                        d_lo := 16#80#;
                    WHEN w_unlock =>
                        d_lo := 16#20#;
                    WHEN w_autoselect  =>
                        d_lo := 16#90#;
                    WHEN w_enter_sec =>
                        d_lo := 16#88#;
                    WHEN OTHERS  =>
                        d_lo :=  0;
                END CASE;

                bus_cycle(bus_cmd => bus_write,
                         byte    => command.byte,
                         data    => d_lo,
                         dataHi  => 0,
                         sector  => 0,
                         address => Addr);
                bus_cycle(bus_cmd => bus_standby,
                         byte    => command.byte);



            WHEN w_unlock_reset =>
                Addr    :=  16#AAA#; --first command byte address
                IF NOT command.byte THEN
                    --if word addressing
                    Addr    := 16#555#; --first command byte address
                END IF;
                bus_cycle(bus_cmd => bus_write,
                         byte    => command.byte,
                         data    => 16#90#,
                         dataHi  => 0,
                         sector  => 0,
                         address => Addr);

                bus_cycle(bus_cmd => bus_standby,
                         byte    => command.byte);

                bus_cycle(bus_cmd => bus_write,
                         byte    => command.byte,
                         data    => 16#F0#,
                         dataHi  => 0,
                         sector  => 0,
                         address => Addr);

                bus_cycle(bus_cmd => bus_standby,
                         byte    => command.byte);

            WHEN w_chip_ers =>
                Addr    :=  16#AAA#; --first command byte address
                IF NOT command.byte THEN
                    --if word addressing
                    Addr    := 16#555#; --first command byte address
                END IF;
                bus_cycle(bus_cmd => bus_write,
                         byte    => command.byte,
                         data    => 16#10#,
                         dataHi  => 0,
                         sector  => 0,
                         Address => Addr);
                FOR i IN 0 TO SecNum LOOP
                    IF Sec_Prot(i)/='1' THEN
                        mem(i) := (OTHERS=>16#FF#);
                    END IF;
                END LOOP;
                bus_cycle(bus_cmd => bus_standby,
                         byte    => command.byte);


            WHEN w_cfi =>
                Addr    :=  16#AA#; --first command byte address
                IF NOT command.byte THEN
                    --if word addressing
                    Addr    := 16#55#; --first command byte address