problems about Behavioral Compiler

[YiYin Wang]

Dear All,
I have used the Behavioral Compiler to synthesize a FIR filter.
I want to constrain a loop. But when I use " find " command to find the
loop, it always reports error and get no results.

the command I used is
"bc_shell> find cell -hierarchy *filter_loop*"
and the feedback is :
"Error: Can't find object '*filter_loop*'.(UID-109)
{}"

How could I solve this problem?

Thanks a lot.
Best Regards

Yiyin Wang
My code is below:

LIBRARY ieee;

USE ieee.std_logic_1164.ALL;

USE ieee.std_logic_arith.ALL;

USE ieee.std_logic_signed.ALL;

ENTITY fir_filter2 IS

PORT (

clk : IN std_logic;

rst : IN std_logic;

load : IN std_logic;

data_in : IN signed( 11 DOWNTO 0 );

coeff_addr : IN unsigned( 3 DOWNTO 0 );

start : IN std_logic;

data_out : OUT signed( 11 DOWNTO 0 )

);

END fir_filter2;

ARCHITECTURE behavioral OF fir_filter2 IS

BEGIN



main_proc: PROCESS



SUBTYPE coeff_element IS signed( 11 DOWNTO 0 );

TYPE coeff_type IS ARRAY ( integer RANGE <> ) OF
coeff_element;

VARIABLE coeff : coeff_type( 0 TO 14 );



SUBTYPE history_element IS signed( 11 DOWNTO 0 );

TYPE history_type IS ARRAY ( integer RANGE <> ) OF
history_element;

VARIABLE history : history_type( 0 TO 14 );



VARIABLE sum : signed( 23 DOWNTO 0 );

ATTRIBUTE unroll_new_instance : boolean;

ATTRIBUTE unroll_new_instance OF sum : VARIABLE IS true;



BEGIN

reset_loop: LOOP


--
-- reset the data output
--

data_out <= ( OTHERS => '0' );


WAIT UNTIL clk'EVENT AND ( clk = '1' );

EXIT reset_loop WHEN ( rst = '1' );




--

-- Initialize all coefficients to zero

--

FOR i IN 0 TO 14 LOOP

coeff( i ) := ( OTHERS => '0' );

END LOOP;



--

-- Initialize history memory to zero

--

FOR i IN 0 TO 14 LOOP

history( i ) := ( OTHERS => '0' );

END LOOP;

main_loop: LOOP



config_loop: LOOP



--

-- Wait until next clock cycle to check for

-- load or filter signals.

--

WAIT UNTIL clk'EVENT AND ( clk = '1' );

EXIT reset_loop WHEN ( rst = '1' );



IF ( start = '1' ) THEN

EXIT config_loop;

END IF;



IF ( load = '1' ) THEN

coeff( conv_integer( '0' & coeff_addr ) ) :=
data_in;

END IF;



END LOOP config_loop;



--

-- Main filter loop

--

filter_loop: LOOP -- pragma n_unroll 3

-- pragma pipeline_init_interval 1



WAIT UNTIL clk'EVENT AND ( clk = '1' );

EXIT reset_loop WHEN ( rst = '1' );



history( 0 ) := signed( data_in );



sum := ( ( ( history( 0 ) * coeff( 0 ) +

history( 1 ) * coeff( 1 ) ) +

( history( 2 ) * coeff( 2 ) +

history( 3 ) * coeff( 3 ) ) ) +

( ( history( 4 ) * coeff( 4 ) +

history( 5 ) * coeff( 5 ) ) +

( history( 6 ) * coeff( 6 ) +

history( 7 ) * coeff( 7 ) ) ) ) +

( ( ( history( 8 ) * coeff( 8 ) +

history( 9 ) * coeff( 9 ) ) +

( history( 10 ) * coeff( 10 ) +

history( 11 ) * coeff( 11 ) ) ) +

( ( history( 12 ) * coeff( 12 ) +

history( 13 ) * coeff( 13 ) ) +

history( 14 ) * coeff( 14 ) ) );



data_out <= sum( 23 DOWNTO 12 );



FOR i IN 14 DOWNTO 1 LOOP

history( i ) := history( i - 1 );

END LOOP;



END LOOP filter_loop;



END LOOP main_loop;



END LOOP reset_loop;



END PROCESS;



END behavioral;