type ALU_STATE is (SIDLE, SADD, SSUB, SMUL, SDIV, SDIV_CALC, SDIV_DONE, SDONE);
signal state_int, state_next : ALU_STATE;
signal done_intern, div_calc_done, div_go_calc : std_logic;
- signal op3_int, op3_next : csigned;
+ signal op3_int, op3_next : csigned := (others => '0');
signal calc_done_int, calc_done_next : std_logic;
-- signale fuer division
signal dividend_msb_int, dividend_msb_next, laengediv_int, laengediv_next : natural;
- signal quo_int, quo_next, aktdiv, aktdiv_next, op1_int, op1_next, op2_int, op2_next : csigned;
+ signal quo_int, quo_next, aktdiv_int, aktdiv_int_next, op1_int, op1_next, op2_int, op2_next : csigned;
signal sign_int, sign_next : std_logic;
begin
op3 <= op3_int;
dividend_msb_int <= 0;
laengediv_int <= 0;
quo_int <= (others => '0');
- aktdiv <= (others => '0');
+ aktdiv_int <= (others => '0');
op1_int <= (others => '0');
op2_int <= (others => '0');
sign_int <= '0';
dividend_msb_int <= dividend_msb_next;
laengediv_int <= laengediv_next;
quo_int <= quo_next;
- aktdiv <= aktdiv_next;
+ aktdiv_int <= aktdiv_int_next;
op1_int <= op1_next;
op2_int <= op2_next;
sign_int <= sign_next;
end process;
-- output
- process(state_int, op1, op2, dividend_msb_int, laengediv_int, quo_int, aktdiv, sign_int, op1_int, op2_int)
- variable tmperg : csigned;
+ process(state_int, op1, op2, dividend_msb_int, laengediv_int, quo_int, aktdiv_int, sign_int, op1_int, op2_int, op3_int)
variable multmp : signed(((2*CBITS)-1) downto 0);
-- vars fuer div
variable laengediv_var, dividend_msb_var : natural;
- variable aktdiv_var, quo_var, op1_var, op2_var : csigned;
+ variable aktdiv_int_var, quo_var, op1_var, op2_var : csigned;
begin
- op3_next <= (others => '0');
calc_done_next <= '0';
div_calc_done <= '0';
div_go_calc <= '0';
dividend_msb_next <= 0;
laengediv_next <= 0;
quo_next <= (others => '0');
- aktdiv_next <= (others => '0');
+ aktdiv_int_next <= (others => '0');
op1_next <= (others => '0');
op2_next <= (others => '0');
sign_next <= '0';
+ op3_next <= (others => '0');
case state_int is
when SIDLE =>
- tmperg := (others => '0');
+ null;
when SADD =>
- tmperg := op1 + op2;
+ op3_next <= op1 + op2;
done_intern <= '1';
when SSUB =>
- tmperg := op1 - op2;
+ op3_next <= op1 - op2;
done_intern <= '1';
when SMUL =>
multmp := op1 * op2;
- tmperg(CBITS-1) := multmp((2*CBITS)-1);
- tmperg((CBITS-2) downto 0) := multmp((CBITS-2) downto 0);
+ op3_next(CBITS-1) <= multmp((2*CBITS)-1);
+ op3_next((CBITS-2) downto 0) <= multmp((CBITS-2) downto 0);
done_intern <= '1';
when SDIV =>
-- division implementiert nach ~hwmod/doc/division.pdf
- tmperg := (others => '0');
if op2 = to_signed(0,CBITS) then
-- TODO: err out signal
done_intern <= '1';
dividend_msb_var := find_msb(op1_var)-1;
laengediv_var := find_msb(op2_var)-1;
- aktdiv_next <= op1_var srl (dividend_msb_var - laengediv_var + 1);
+ aktdiv_int_next <= op1_var srl (dividend_msb_var - laengediv_var + 1);
div_go_calc <= '1';
dividend_msb_next <= dividend_msb_var;
sign_next <= op1(CBITS-1) xor op2(CBITS-1);
end if;
when SDIV_CALC =>
- tmperg := (others => '0');
-
if (dividend_msb_int - laengediv_int + 1) > 0 then
- aktdiv_var := aktdiv sll 1;
- aktdiv_var(0) := op1_int(dividend_msb_int - laengediv_int);
+ aktdiv_int_var := aktdiv_int sll 1;
+ aktdiv_int_var(0) := op1_int(dividend_msb_int - laengediv_int);
quo_var := quo_int sll 1;
- if aktdiv_var >= op2_int then
+ if aktdiv_int_var >= op2_int then
quo_var(0) := '1';
- aktdiv_var := aktdiv_var - op2_int;
+ aktdiv_int_var := aktdiv_int_var - op2_int;
end if;
quo_next <= quo_var;
- aktdiv_next <= aktdiv_var;
+ aktdiv_int_next <= aktdiv_int_var;
dividend_msb_next <= dividend_msb_int;
laengediv_next <= laengediv_int + 1;
op1_next <= op1_int;
div_calc_done <= '1';
end if;
when SDIV_DONE =>
- tmperg := quo_int;
+ op3_next <= quo_int;
done_intern <= '1';
when SDONE =>
- done_intern <= '1';
calc_done_next <= '1';
- op3_next <= tmperg;
- tmperg := (others => '0');
+ op3_next <= op3_int;
end case;
end process;
end architecture beh;