--------------------------------------------------
-- Model        :   8051 Behavioral Model,
--                  VHDL Entity mc8051.program_ctrl.interface
--
-- Author       :   Michael Mayer (mrmayer@computer.org),
--                  Dr. Hardy J. Pottinger,
--                  Department of Electrical Engineering
--                  University of Missouri - Rolla
--
-- Created at   :   09/22/98 14:04:05
--
LIBRARY ieee ;
USE ieee.std_logic_1164.all;
USE ieee.numeric_std.all;
LIBRARY mc8051 ;
USE mc8051.synth_pack.all;

ENTITY program_ctrl IS
   PORT( 
      cmp_true : IN     std_logic ;
      cycle_states : IN     std_logic_vector( 3 DOWNTO 0 )  ;
      dptr : IN     std_logic_vector( 15 DOWNTO 0 )  ;
      int_clk : IN     std_logic ;
      int_rst : IN     std_logic ;
      pdata : IN     std_logic_vector( 7 DOWNTO 0 )  ;
      rd_pmem1 : IN     std_logic ;
      rd_pmem2 : IN     std_logic ;
      addr_gb : OUT    std_logic_vector( 7 DOWNTO 0 )  ;
      dec_rd_sp : OUT    std_logic ;
      inc_wr_sp : OUT    std_logic ;
      indirect_sel : OUT    std_logic ;
      ir : OUT    std_logic_vector( 7 DOWNTO 0 )  ;
      last_cycle : OUT    std_logic ;
      new_ir : OUT    std_logic ;
      pdat_loc : OUT    std_logic_vector( 15 DOWNTO 0 )  ;
      rd_gb : OUT    std_logic ;
      wr_gb : OUT    std_logic ;
      acknow : INOUT  std_logic ;
      data_gb : INOUT  std_logic_vector( 7 DOWNTO 0 ) 
   );

-- Declarations

END program_ctrl ;
--
-- VHDL Architecture mc8051.program_ctrl.struct
--
-- Created:
--          by - mrmayer.UNKNOWN (eceultra3.ece.umr.edu)
--          at - 14:04:08 09/22/98
--
-- Generated by Mentor Graphics' Renoir(TM) 3.4 (Build 18)
--
LIBRARY ieee ;
USE ieee.std_logic_1164.all;
USE ieee.std_logic_arith.conv_std_logic_vector;
USE ieee.numeric_std.all;
USE ieee.std_logic_textio.all;
USE std.textio.ALL;
LIBRARY mc8051 ;
USE mc8051.synth_pack.all;
USE mc8051.pack8051.to_int;

architecture tb of program_ctrl is

    TYPE memory_array IS
       ARRAY (natural RANGE 0 TO 1023) OF std_logic_vector(7  DOWNTO 0);
begin


   p1: process (cycle_states) IS
    PROCEDURE load_hex (mem: INOUT memory_array ) IS
 
        FILE     progfile       : TEXT OPEN read_mode IS "program.hex";
        VARIABLE L              : LINE;
        VARIABLE ch             : CHARACTER;
        VARIABLE rec_type       : CHARACTER;
        VARIABLE sum            : INTEGER;
        VARIABLE dig            : INTEGER;
        VARIABLE data           : INTEGER;
        VARIABLE numb_of_bytes  : INTEGER;
        VARIABLE address        : INTEGER;
        VARIABLE address_offset : INTEGER;
        VARIABLE end_of_data    : BOOLEAN;
        VARIABLE checksum       : INTEGER;
        VARIABLE line_num       : INTEGER;
 
        BEGIN
            line_num := 0;
            address_offset := 0;
            end_of_data := FALSE;
            WHILE NOT (endfile(progfile) OR end_of_data) LOOP
                -- Reset the variables for the line
                sum := 0;
                address := 0;
                line_num := line_num + 1;
 
                readline(progfile, L);
                -- Read in the : character
                read(L, ch);
                IF ch /= ':' THEN
                    NEXT;  -- go to next loop
                END IF;
 
                -- Read in the number of bytes
                read(L, ch);  -- msb
                dig := to_int(ch);
                sum := sum + dig;
                read(L, ch);  -- lsb
                sum := sum + to_int(ch);
                numb_of_bytes := dig*16 + to_int(ch);
 
                -- Read in the address
                FOR k IN 3 DOWNTO 0 LOOP
                    read(L, ch);
                    dig := to_int(ch);
                    sum := sum + dig;
                    address := address + dig * 16**k;
                END LOOP;
 
                -- Read in the record type
                read(L,ch);
                sum := sum + to_int(ch);
                ASSERT ch = '0'
                    REPORT "Illegal Record Type - Bad Program File" &
                           " on line " & INTEGER'IMAGE(line_num);
                read(L,rec_type);
                sum := sum + to_int(rec_type);
 
                -- If it is a line of all zeros, then it is the end of data.
                IF (numb_of_bytes = 0) AND (address = 0)THEN
                    end_of_data := TRUE;
 
                -- If it is normal data, then read in all of the bytes to program_mem
                ELSIF rec_type = '0' THEN  -- It has normal data
                    FOR byte_no IN 0 TO numb_of_bytes-1 LOOP
                         read(L,ch);
                         dig := to_int(ch);
                         sum := sum + dig;
                         read(L,ch);
                         sum := sum + to_int(ch);
                         data := dig*16 + to_int(ch);
                         mem(address_offset*16 + address + byte_no) :=
                            conv_std_logic_vector(data,8);
                    END LOOP;
 
                -- If it is an end of file record, then set end_of_data true
                ELSIF rec_type = '1' THEN -- it is an end of file record
                    end_of_data := TRUE;
                ELSIF rec_type = '2' THEN
                    address_offset := 0;
                    FOR k IN 3 DOWNTO 0 LOOP
                        read(L, ch);
                        dig := to_int(ch);
                        sum := sum + dig;
                        address_offset := address_offset + dig*16**k;
                    END LOOP;
                END IF;
 
                -- get the checksum
                read(L,ch);
                dig := to_int(ch);
                read(L,ch);
                checksum := dig * 16 + to_int(ch);
                --ASSERT (checksum + sum MOD 256) = 0;
                --   REPORT "Checksum Error"& " on line " & INTEGER'IMAGE(line_num);
            END LOOP;
        END PROCEDURE load_hex;

 
    VARIABLE mem: memory_array;
    VARIABLE address : natural;
    VARIABLE write_data: std_logic_vector(7 DOWNTO 0);
    VARIABLE initialized : BOOLEAN := FALSE;

   BEGIN
      IF NOT initialized THEN
          load_hex(mem);
          initialized := TRUE;
      END IF;

      new_ir <= '0';
      IF cycle_states = s1p1 THEN
          ir <= mem(address);
          address := address + 1;
          IF rising_edge(int_clk) THEN
              new_ir <= '1';
          END IF;
      END IF;
   END PROCESS p1;

END ARCHITECTURE tb;