+
+ function ascii2sc (x : hbyte) return hbyte is
+ variable y : hbyte;
+ begin
+ case x is
+ when x"30" => y := SC_KP_0;
+ when x"31" => y := SC_KP_1;
+ when x"32" => y := SC_KP_2;
+ when x"33" => y := SC_KP_3;
+ when x"34" => y := SC_KP_4;
+ when x"35" => y := SC_KP_5;
+ when x"36" => y := SC_KP_6;
+ when x"37" => y := SC_KP_7;
+ when x"38" => y := SC_KP_8;
+ when x"39" => y := SC_KP_9;
+ when x"2b" => y := SC_KP_PLUS;
+ when x"2d" => y := SC_KP_MINUS;
+ when x"2a" => y := SC_KP_MUL;
+ when x"2f" => y := SC_KP_DIV;
+ when x"20" => y := SC_SPACE;
+ when x"1c" => y := SC_ENTER;
+ when x"0e" => y := SC_BKSP;
+ when others => y := x"41";
+ end case;
+ return y;
+ end function;
+
+ function valid_char (x : hbyte) return boolean is
+ variable y : boolean;
+ begin
+ case x is
+ when SC_KP_0 | SC_KP_1 | SC_KP_2 | SC_KP_3 |
+ SC_KP_4 | SC_KP_5 | SC_KP_6 | SC_KP_7 |
+ SC_KP_8 | SC_KP_9 | SC_KP_PLUS |
+ SC_KP_MINUS | SC_KP_MUL |
+ SC_KP_DIV | SC_SPACE |
+ SC_BKSP | SC_ENTER =>
+ y := true;
+ when others => y := false;
+ end case;
+ return y;
+ end function;
+
+ function zeile2char(i : std_logic_vector; stelle : natural) return hbyte is
+ subtype zeilnum is string(1 to 2);
+ type zeilnum_arr is array (natural range 0 to 49) of zeilnum;
+ constant zn : zeilnum_arr := (
+ 0 => "00", 1 => "01", 2 => "02", 3 => "03", 4 => "04",
+ 5 => "05", 6 => "06", 7 => "07", 8 => "08", 9 => "09",
+ 10 => "10", 11 => "11", 12 => "12", 13 => "13", 14 => "14",
+ 15 => "15", 16 => "16", 17 => "17", 18 => "18", 19 => "19",
+ 20 => "20", 21 => "21", 22 => "22", 23 => "23", 24 => "24",
+ 25 => "25", 26 => "26", 27 => "27", 28 => "28", 29 => "29",
+ 30 => "30", 31 => "31", 32 => "32", 33 => "33", 34 => "34",
+ 35 => "35", 36 => "36", 37 => "37", 38 => "38", 39 => "39",
+ 40 => "40", 41 => "41", 42 => "42", 43 => "43", 44 => "44",
+ 45 => "45", 46 => "46", 47 => "47", 48 => "48", 49 => "49",
+ others => "xy");
+ variable t : signed(hzeile'length downto 0);
+ begin
+ t := signed('0' & i);
+ t := t / 2;
+ return hbyte(to_unsigned(character'pos(zn(to_integer(t))(stelle)),8));
+ end;