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https://opencores.org/ocsvn/mlite/mlite/trunk
Subversion Repositories mlite
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- from Rev 120 to Rev 121
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Rev 120 → Rev 121
/trunk/vhdl/mult.vhd
1,6 → 1,7
--------------------------------------------------------------------- |
-- TITLE: Multiplication and Division Unit |
-- AUTHOR: Steve Rhoads (rhoadss@yahoo.com) |
-- AUTHORS: Steve Rhoads (rhoadss@yahoo.com) |
-- Matthias Gruenewald |
-- DATE CREATED: 1/31/01 |
-- FILENAME: mult.vhd |
-- PROJECT: Plasma CPU core |
31,9 → 32,12
-- } |
-- reg_b = reg_b >> 1; |
--------------------------------------------------------------------- |
--library ieee, MLITE_LIB; |
--use MLITE_LIB.all; |
library ieee; |
use ieee.std_logic_1164.all; |
use ieee.std_logic_unsigned.all; |
use IEEE.std_logic_arith.all; |
use work.mlite_pack.all; |
|
entity mult is |
47,6 → 51,7
end; --entity mult |
|
architecture logic of mult is |
|
-- type mult_function_type is ( |
-- mult_nothing, mult_read_lo, mult_read_hi, mult_write_lo, |
-- mult_write_hi, mult_mult, mult_divide, mult_signed_divide); |
58,209 → 63,476
signal answer_reg : std_logic_vector(31 downto 0); |
signal aa, bb : std_logic_vector(33 downto 0); |
signal sum : std_logic_vector(33 downto 0); |
signal sum2 : std_logic_vector(67 downto 0); |
signal reg_a_times3 : std_logic_vector(33 downto 0); |
signal sign_extend_sig : std_logic; |
|
--Used in Xilinx tri-state area optimizated version |
signal SUB_Y, A_PROCESSED, B_PROCESSED, A_REG, B_REG : std_logic_vector(31 downto 0); |
signal DIV_Y, DIV_Y_IN, DIV_Y_IN_CALC, DIV_Y_IN_INIT, Y_IN, Y_IN2, MULT_Y, Y : std_logic_vector(63 downto 0) := (others => '0'); |
signal SAVE_Y, SAVE_DIV_Y, MULT_ND, MULT_RDY, DO_SIGNED, DIV_ND : std_logic; |
signal DIV_COUNT, INVERT_A, INVERT_B, INVERT_Y, DIV_RDY : std_logic; |
signal DIV_COUNTER : std_logic_vector(4 downto 0); |
signal PAUSE_IN, SAVE_PAUSE, PAUSE : std_logic := '0'; |
signal MULT_RFD : std_logic; |
signal a_temp_sig, a_neg_sig, b_neg_sig : std_logic_vector(31 downto 0); |
signal b_temp_sig : std_logic_vector(63 downto 0); |
signal a_msb, b_msb : std_logic; |
signal answer_temp_sig : std_logic_vector(31 downto 0); |
signal aa_select : std_logic_vector(3 downto 0); |
signal bb_select : std_logic_vector(1 downto 0); |
signal a_select : std_logic_vector(4 downto 0); |
signal b_select : std_logic_vector(11 downto 0); |
signal answer_select : std_logic_vector(2 downto 0); |
|
begin |
|
--sum = aa + bb |
generic_adder: if adder_type = "GENERIC" generate |
sum <= (aa + bb) when do_mult_reg = '1' else |
(aa - bb); |
end generate; --generic_adder |
|
--multiplication/division unit |
mult_proc: process(clk, a, b, mult_func, |
do_mult_reg, do_signed_reg, count_reg, |
reg_a, reg_b, answer_reg, sum, reg_a_times3) |
variable do_mult_temp : std_logic; |
variable do_signed_temp : std_logic; |
variable count_temp : std_logic_vector(5 downto 0); |
variable a_temp : std_logic_vector(31 downto 0); |
variable b_temp : std_logic_vector(63 downto 0); |
variable answer_temp : std_logic_vector(31 downto 0); |
variable start : std_logic; |
variable do_write : std_logic; |
variable do_hi : std_logic; |
variable sign_extend : std_logic; |
variable a_neg : std_logic_vector(31 downto 0); |
variable b_neg : std_logic_vector(31 downto 0); |
--For Altera: sum = aa + bb |
lpm_adder: if adder_type = "ALTERA" generate |
lpm_add_sub_component : lpm_add_sub |
GENERIC MAP ( |
lpm_width => 34, |
lpm_direction => "UNUSED", |
lpm_type => "LPM_ADD_SUB", |
lpm_hint => "ONE_INPUT_IS_CONSTANT=NO" |
) |
PORT MAP ( |
dataa => aa, |
add_sub => do_mult_reg, |
datab => bb, |
result => sum |
); |
end generate; --lpm_adder |
|
begin |
do_mult_temp := do_mult_reg; |
do_signed_temp := do_signed_reg; |
count_temp := count_reg; |
a_temp := reg_a; |
b_temp := reg_b; |
answer_temp := answer_reg; |
sign_extend := do_signed_reg and do_mult_reg; |
start := '0'; |
do_write := '0'; |
do_hi := '0'; |
-- Negate signals |
a_neg_sig <= bv_negate(a); |
b_neg_sig <= bv_negate(b); |
sign_extend_sig <= do_signed_reg and do_mult_reg; |
|
-- Result |
c_mult <= reg_b(31 downto 0) when mult_func=mult_read_lo else |
reg_b(63 downto 32) when mult_func=mult_read_hi else |
ZERO; |
|
case mult_func is |
when mult_read_lo => |
when mult_read_hi => |
do_hi := '1'; |
when mult_write_lo => |
do_write := '1'; |
when mult_write_hi => |
do_write := '1'; |
do_hi := '1'; |
when mult_mult => |
start := '1'; |
do_mult_temp := '1'; |
do_signed_temp := '0'; |
when mult_signed_mult => |
start := '1'; |
do_mult_temp := '1'; |
do_signed_temp := '1'; |
when mult_divide => |
start := '1'; |
do_mult_temp := '0'; |
do_signed_temp := '0'; |
when mult_signed_divide => |
start := '1'; |
do_mult_temp := '0'; |
do_signed_temp := a(31) xor b(31); |
when others => |
end case; |
|
if start = '1' then |
count_temp := "000000"; |
answer_temp := ZERO; |
a_neg := bv_negate(a); |
b_neg := bv_negate(b); |
if do_mult_temp = '0' then |
b_temp(63) := '0'; |
if mult_func /= mult_signed_divide or a(31) = '0' then |
a_temp := a; |
else |
a_temp := a_neg; |
GENERIC_MULT: if MULT_TYPE="GENERIC" generate |
|
--multiplication/division unit |
mult_proc: process(clk, a, b, mult_func, |
do_mult_reg, do_signed_reg, count_reg, |
reg_a, reg_b, answer_reg, sum, reg_a_times3) |
variable do_mult_temp : std_logic; |
variable do_signed_temp : std_logic; |
variable count_temp : std_logic_vector(5 downto 0); |
variable a_temp : std_logic_vector(31 downto 0); |
variable b_temp : std_logic_vector(63 downto 0); |
variable answer_temp : std_logic_vector(31 downto 0); |
variable start : std_logic; |
variable do_write : std_logic; |
variable do_hi : std_logic; |
variable sign_extend : std_logic; |
|
begin |
do_mult_temp := do_mult_reg; |
do_signed_temp := do_signed_reg; |
count_temp := count_reg; |
a_temp := reg_a; |
b_temp := reg_b; |
answer_temp := answer_reg; |
sign_extend := do_signed_reg and do_mult_reg; |
start := '0'; |
do_write := '0'; |
do_hi := '0'; |
|
case mult_func is |
when mult_read_lo => |
when mult_read_hi => |
do_hi := '1'; |
when mult_write_lo => |
do_write := '1'; |
when mult_write_hi => |
do_write := '1'; |
do_hi := '1'; |
when mult_mult => |
start := '1'; |
do_mult_temp := '1'; |
do_signed_temp := '0'; |
when mult_signed_mult => |
start := '1'; |
do_mult_temp := '1'; |
do_signed_temp := '1'; |
when mult_divide => |
start := '1'; |
do_mult_temp := '0'; |
do_signed_temp := '0'; |
when mult_signed_divide => |
start := '1'; |
do_mult_temp := '0'; |
do_signed_temp := a(31) xor b(31); |
when others => |
end case; |
|
if start = '1' then |
count_temp := "000000"; |
answer_temp := ZERO; |
if do_mult_temp = '0' then |
b_temp(63) := '0'; |
if mult_func /= mult_signed_divide or a(31) = '0' then |
a_temp := a; |
else |
a_temp := a_neg_sig; |
end if; |
if mult_func /= mult_signed_divide or b(31) = '0' then |
b_temp(62 downto 31) := b; |
else |
b_temp(62 downto 31) := b_neg_sig; |
end if; |
b_temp(30 downto 0) := ZERO(30 downto 0); |
else --multiply |
if do_signed_temp = '0' or b(31) = '0' then |
a_temp := a; |
b_temp(31 downto 0) := b; |
else |
a_temp := a_neg_sig; |
b_temp(31 downto 0) := b_neg_sig; |
end if; |
b_temp(63 downto 32) := ZERO; |
end if; |
if mult_func /= mult_signed_divide or b(31) = '0' then |
b_temp(62 downto 31) := b; |
elsif do_write = '1' then |
if do_hi = '0' then |
b_temp(31 downto 0) := a; |
else |
b_temp(62 downto 31) := b_neg; |
b_temp(63 downto 32) := a; |
end if; |
b_temp(30 downto 0) := ZERO(30 downto 0); |
else --multiply |
if do_signed_temp = '0' or b(31) = '0' then |
a_temp := a; |
b_temp(31 downto 0) := b; |
else |
a_temp := a_neg; |
b_temp(31 downto 0) := b_neg; |
end if; |
|
if do_mult_reg = '0' then --division |
aa <= (reg_a(31) and sign_extend) & (reg_a(31) and sign_extend) & reg_a; |
bb <= reg_b(33 downto 0); |
else --multiplication two-bits at a time |
case reg_b(1 downto 0) is |
when "00" => |
aa <= "00" & ZERO; |
when "01" => |
aa <= (reg_a(31) and sign_extend) & (reg_a(31) and sign_extend) & reg_a; |
when "10" => |
aa <= (reg_a(31) and sign_extend) & reg_a & '0'; |
when others => |
aa <= reg_a_times3; |
end case; |
bb <= (reg_b(63) and sign_extend) & (reg_b(63) and sign_extend) & reg_b(63 downto 32); |
end if; |
|
if count_reg(5) = '0' and start = '0' then |
count_temp := bv_inc6(count_reg); |
if do_mult_reg = '0' then --division |
answer_temp(31 downto 1) := answer_reg(30 downto 0); |
if reg_b(63 downto 32) = ZERO and sum(32) = '0' then |
a_temp := sum(31 downto 0); --aa=aa-bb; |
answer_temp(0) := '1'; |
else |
answer_temp(0) := '0'; |
end if; |
if count_reg /= "011111" then |
b_temp(62 downto 0) := reg_b(63 downto 1); |
else --done with divide |
b_temp(63 downto 32) := a_temp; |
if do_signed_reg = '0' then |
b_temp(31 downto 0) := answer_temp; |
else |
b_temp(31 downto 0) := bv_negate(answer_temp); |
end if; |
end if; |
else -- mult_mode |
b_temp(63 downto 30) := sum; |
b_temp(29 downto 0) := reg_b(31 downto 2); |
if count_reg = "001000" and sign_extend = '0' and --early stop |
reg_b(15 downto 0) = ZERO(15 downto 0) then |
count_temp := "111111"; |
b_temp(31 downto 0) := reg_b(47 downto 16); |
end if; |
if count_reg = "000100" and sign_extend = '0' and --early stop |
reg_b(23 downto 0) = ZERO(23 downto 0) then |
count_temp := "111111"; |
b_temp(31 downto 0) := reg_b(55 downto 24); |
end if; |
count_temp(5) := count_temp(4); |
end if; |
b_temp(63 downto 32) := ZERO; |
end if; |
elsif do_write = '1' then |
if do_hi = '0' then |
b_temp(31 downto 0) := a; |
|
if rising_edge(clk) then |
do_mult_reg <= do_mult_temp; |
do_signed_reg <= do_signed_temp; |
count_reg <= count_temp; |
reg_a <= a_temp; |
reg_b <= b_temp; |
answer_reg <= answer_temp; |
if start = '1' then |
reg_a_times3 <= ((a_temp(31) and do_signed_temp) & a_temp & '0') + |
((a_temp(31) and do_signed_temp) & (a_temp(31) and do_signed_temp) & a_temp); |
end if; |
end if; |
|
if count_reg(5) = '0' and mult_func /= mult_nothing and start = '0' then |
pause_out <= '1'; |
else |
b_temp(63 downto 32) := a; |
pause_out <= '0'; |
end if; |
end if; |
|
end process; |
|
if do_mult_reg = '0' then --division |
aa <= (reg_a(31) and sign_extend) & (reg_a(31) and sign_extend) & reg_a; |
bb <= reg_b(33 downto 0); |
else --multiplication two-bits at a time |
case reg_b(1 downto 0) is |
when "00" => |
aa <= "00" & ZERO; |
when "01" => |
aa <= (reg_a(31) and sign_extend) & (reg_a(31) and sign_extend) & reg_a; |
when "10" => |
aa <= (reg_a(31) and sign_extend) & reg_a & '0'; |
when others => |
aa <= reg_a_times3; |
end generate; |
|
|
AREA_OPTIMIZED_MULT: if MULT_TYPE="AREA_OPTIMIZED" generate |
--Xilinx Tristate size optimization by Matthias Gruenewald |
|
--multiplication/division unit |
mult_proc: process(a, b, clk, count_reg, do_mult_reg, do_signed_reg, mult_func, reg_b, sum) |
variable do_mult_temp : std_logic; |
variable do_signed_temp : std_logic; |
variable count_temp : std_logic_vector(5 downto 0); |
variable start : std_logic; |
variable do_write : std_logic; |
variable do_hi : std_logic; |
variable sign_extend : std_logic; |
|
begin |
do_mult_temp := do_mult_reg; |
do_signed_temp := do_signed_reg; |
count_temp := count_reg; |
sign_extend := do_signed_reg and do_mult_reg; |
sign_extend_sig <= sign_extend; |
start := '0'; |
do_write := '0'; |
do_hi := '0'; |
a_select <= (others => '0'); |
b_select <= (others => '0'); |
aa_select <= (others => '0'); |
bb_select <= (others => '0'); |
answer_select <= (others => '0'); |
|
case mult_func is |
when mult_read_lo => |
when mult_read_hi => |
do_hi := '1'; |
when mult_write_lo => |
do_write := '1'; |
when mult_write_hi => |
do_write := '1'; |
do_hi := '1'; |
when mult_mult => |
start := '1'; |
do_mult_temp := '1'; |
do_signed_temp := '0'; |
when mult_signed_mult => |
start := '1'; |
do_mult_temp := '1'; |
do_signed_temp := '1'; |
when mult_divide => |
start := '1'; |
do_mult_temp := '0'; |
do_signed_temp := '0'; |
when mult_signed_divide => |
start := '1'; |
do_mult_temp := '0'; |
do_signed_temp := a(31) xor b(31); |
when others => |
end case; |
bb <= (reg_b(63) and sign_extend) & (reg_b(63) and sign_extend) & reg_b(63 downto 32); |
end if; |
|
if count_reg(5) = '0' and start = '0' then |
count_temp := bv_inc6(count_reg); |
if do_mult_reg = '0' then --division |
answer_temp(31 downto 1) := answer_reg(30 downto 0); |
if reg_b(63 downto 32) = ZERO and sum(32) = '0' then |
a_temp := sum(31 downto 0); --aa=aa-bb; |
answer_temp(0) := '1'; |
else |
answer_temp(0) := '0'; |
end if; |
if count_reg /= "011111" then |
b_temp(62 downto 0) := reg_b(63 downto 1); |
else --done with divide |
b_temp(63 downto 32) := a_temp; |
if start = '1' then |
count_temp := "000000"; |
answer_select(0)<='1'; |
--answer_temp := ZERO; |
if do_mult_temp = '0' then |
--b_temp(63) := '0'; |
if mult_func /= mult_signed_divide or a(31) = '0' then |
a_select(0) <= '1'; |
--a_temp := a; |
else |
a_select(1) <= '1'; |
--a_temp := a_neg; |
end if; |
if mult_func /= mult_signed_divide or b(31) = '0' then |
b_select(0) <= '1'; |
--b_temp(62 downto 31) := b; |
else |
b_select(1) <= '1'; |
--b_temp(62 downto 31) := b_neg; |
end if; |
--b_temp(30 downto 0) := ZERO(30 downto 0); |
else --multiply |
if do_signed_temp = '0' or b(31) = '0' then |
a_select(2) <= '1'; |
--a_temp := a; |
b_select(2) <= '1'; |
--b_temp(31 downto 0) := b; |
else |
a_select(3) <= '1'; |
--a_temp := a_neg; |
b_select(3) <= '1'; |
--b_temp(31 downto 0) := b_neg; |
end if; |
--b_temp(63 downto 32) := ZERO; |
end if; |
elsif do_write = '1' then |
if do_hi = '0' then |
b_select(4) <= '1'; |
--b_temp(31 downto 0) := a; |
else |
b_select(5) <= '1'; |
--b_temp(63 downto 32) := a; |
end if; |
end if; |
|
if do_mult_reg = '0' then --division |
aa_select(0) <= '1'; |
--aa <= (reg_a(31) and sign_extend) & (reg_a(31) and sign_extend) & reg_a; |
bb_select(0) <= '1'; |
--bb <= reg_b(33 downto 0); |
else --multiplication two-bits at a time |
case reg_b(1 downto 0) is |
when "00" => |
aa_select(1) <= '1'; |
--aa <= "00" & ZERO; |
when "01" => |
aa_select(2) <= '1'; |
--aa <= (reg_a(31) and sign_extend) & (reg_a(31) and sign_extend) & reg_a; |
when "10" => |
aa_select(3) <= '1'; |
--aa <= (reg_a(31) and sign_extend) & reg_a & '0'; |
when others => |
--aa_select(4) <= '1'; |
--aa <= reg_a_times3; |
end case; |
bb_select(1) <= '1'; |
--bb <= (reg_b(63) and sign_extend) & (reg_b(63) and sign_extend) & reg_b(63 downto 32); |
end if; |
|
if count_reg(5) = '0' and start = '0' then |
count_temp := bv_inc6(count_reg); |
if do_mult_reg = '0' then --division |
--answer_temp(31 downto 1) := answer_reg(30 downto 0); |
if reg_b(63 downto 32) = ZERO and sum(32) = '0' then |
a_select(4) <= '1'; |
--a_temp := sum(31 downto 0); --aa=aa-bb; |
answer_select(1) <= '1'; |
--answer_temp(0) := '1'; |
else |
answer_select(2) <= '1'; |
--answer_temp(0) := '0'; |
end if; |
if count_reg /= "011111" then |
--b_temp(62 downto 0) := reg_b(63 downto 1); |
b_select(6) <= '1'; |
else --done with divide |
--b_temp(63 downto 32) := a_temp; |
if do_signed_reg = '0' then |
b_temp(31 downto 0) := answer_temp; |
b_select(7) <= '1'; |
--b_temp(31 downto 0) := answer_temp; |
else |
b_temp(31 downto 0) := bv_negate(answer_temp); |
b_select(8) <= '1'; |
--b_temp(31 downto 0) := bv_negate(answer_temp); |
end if; |
end if; |
else -- mult_mode |
b_temp(63 downto 30) := sum; |
b_temp(29 downto 0) := reg_b(31 downto 2); |
if count_reg = "001000" and sign_extend = '0' and --early stop |
reg_b(15 downto 0) = ZERO(15 downto 0) then |
end if; |
else -- mult_mode |
b_select(9) <= '1'; |
--b_temp(63 downto 30) := sum; |
--b_temp(29 downto 0) := reg_b(31 downto 2); |
if count_reg = "001000" and sign_extend = '0' and --early stop |
reg_b(15 downto 0) = ZERO(15 downto 0) then |
count_temp := "111111"; |
b_temp(31 downto 0) := reg_b(47 downto 16); |
end if; |
if count_reg = "000100" and sign_extend = '0' and --early stop |
reg_b(23 downto 0) = ZERO(23 downto 0) then |
b_select(10) <= '1'; |
--b_temp(31 downto 0) := reg_b(47 downto 16); |
end if; |
if count_reg = "000100" and sign_extend = '0' and --early stop |
reg_b(23 downto 0) = ZERO(23 downto 0) then |
count_temp := "111111"; |
b_temp(31 downto 0) := reg_b(55 downto 24); |
end if; |
count_temp(5) := count_temp(4); |
b_select(11) <= '1'; |
--b_temp(31 downto 0) := reg_b(55 downto 24); |
end if; |
count_temp(5) := count_temp(4); |
end if; |
end if; |
end if; |
|
if rising_edge(clk) then |
do_mult_reg <= do_mult_temp; |
do_signed_reg <= do_signed_temp; |
count_reg <= count_temp; |
reg_a <= a_temp; |
reg_b <= b_temp; |
answer_reg <= answer_temp; |
if start = '1' then |
reg_a_times3 <= ((a_temp(31) and do_signed_temp) & a_temp & '0') + |
((a_temp(31) and do_signed_temp) & (a_temp(31) and do_signed_temp) & a_temp); |
if rising_edge(clk) then |
do_mult_reg <= do_mult_temp; |
do_signed_reg <= do_signed_temp; |
count_reg <= count_temp; |
reg_a <= a_temp_sig; |
reg_b <= b_temp_sig; |
answer_reg <= answer_temp_sig; |
if start = '1' then |
reg_a_times3 <= ((a_temp_sig(31) and do_signed_temp) & a_temp_sig & '0') + |
((a_temp_sig(31) and do_signed_temp) & (a_temp_sig(31) and do_signed_temp) & a_temp_sig); |
end if; |
end if; |
end if; |
|
if count_reg(5) = '0' and mult_func/= mult_nothing and start = '0' then |
pause_out <= '1'; |
else |
pause_out <= '0'; |
end if; |
case mult_func is |
when mult_read_lo => |
c_mult <= reg_b(31 downto 0); |
when mult_read_hi => |
c_mult <= reg_b(63 downto 32); |
when others => |
c_mult <= ZERO; |
end case; |
if count_reg(5) = '0' and mult_func/= mult_nothing and start = '0' then |
pause_out <= '1'; |
else |
pause_out <= '0'; |
end if; |
|
end process; |
|
end process; |
|
-- Arguments |
a_msb <= reg_a(31) and sign_extend_sig; |
aa <= a_msb & a_msb & reg_a when aa_select(0)='1' else |
"00" & ZERO when aa_select(1)='1' else |
a_msb & a_msb & reg_a when aa_select(2)='1' else |
a_msb & reg_a & '0' when aa_select(3)='1' else |
reg_a_times3; |
|
generic_adder: |
if adder_type = "GENERIC" generate |
sum <= (aa + bb) when do_mult_reg = '1' else |
(aa - bb); |
end generate; --generic_adder |
b_msb <= reg_b(63) and sign_extend_sig; |
bb <= reg_b(33 downto 0) when bb_select(0)='1' else (others => 'Z'); |
bb <= b_msb & b_msb & reg_b(63 downto 32) when bb_select(1)='1' else (others => 'Z'); |
|
--For Altera |
lpm_adder: |
if adder_type = "ALTERA" generate |
lpm_add_sub_component : lpm_add_sub |
GENERIC MAP ( |
lpm_width => 34, |
lpm_direction => "UNUSED", |
lpm_type => "LPM_ADD_SUB", |
lpm_hint => "ONE_INPUT_IS_CONSTANT=NO" |
) |
PORT MAP ( |
dataa => aa, |
add_sub => do_mult_reg, |
datab => bb, |
result => sum |
); |
end generate; --lpm_adder |
-- Divide: Init |
a_temp_sig <= a when a_select(0)='1' else (others => 'Z'); |
a_temp_sig <= a_neg_sig when a_select(1)='1' else (others => 'Z'); |
b_temp_sig <= '0' & b & ZERO(30 downto 0) when b_select(0)='1' else (others => 'Z'); |
b_temp_sig <= '0' & b_neg_sig & ZERO(30 downto 0) when b_select(1)='1' else (others => 'Z'); |
|
-- Multiply: Init |
a_temp_sig <= a when a_select(2)='1' else (others => 'Z'); |
b_temp_sig <= ZERO & b when b_select(2)='1' else (others => 'Z'); |
a_temp_sig <= a_neg_sig when a_select(3)='1' else (others => 'Z'); |
b_temp_sig <= ZERO & b_neg_sig when b_select(3)='1' else (others => 'Z'); |
|
-- Intermediate results |
b_temp_sig <= reg_b(63 downto 32) & a when b_select(4)='1' else (others => 'Z'); |
b_temp_sig <= a & reg_b(31 downto 0) when b_select(5)='1' else (others => 'Z'); |
|
-- Divide: Operation |
a_temp_sig <= sum(31 downto 0) when a_select(4)='1' else (others => 'Z'); |
b_temp_sig <= reg_b(63) & reg_b(63 downto 1) when b_select(6)='1' else (others => 'Z'); |
b_temp_sig <= a_temp_sig & answer_temp_sig when b_select(7)='1' else (others => 'Z'); |
b_temp_sig <= a_temp_sig & bv_negate(answer_temp_sig) when b_select(8)='1' else (others => 'Z'); |
|
-- Multiply: Operation |
b_temp_sig <= sum & reg_b(31 downto 2) when b_select(9)='1' and b_select(10)='0' and b_select(11)='0' else (others => 'Z'); |
b_temp_sig <= sum(33 downto 2) & reg_b(47 downto 16) when b_select(10)='1' else (others => 'Z'); |
b_temp_sig <= sum(33 downto 2) & reg_b(55 downto 24) when b_select(11)='1' else (others => 'Z'); |
|
-- Default values |
a_temp_sig <= reg_a when conv_integer(unsigned(a_select))=0 else (others => 'Z'); |
b_temp_sig <= reg_b when conv_integer(unsigned(b_select))=0 else (others => 'Z'); |
|
-- Result |
answer_temp_sig <= ZERO when answer_select(0)='1' else |
answer_reg(30 downto 0) & '1' when answer_select(1)='1' else |
answer_reg(30 downto 0) & '0' when answer_select(2)='1' else |
answer_reg; |
|
end generate; |
|
end; --architecture logic |
|