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- added coef_latency

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- y_dout registered


git-svn-id: http://moon:8086/svn/vhdl/trunk@187 cc03376c-175c-47c8-b038-4cd826a8556b
This commit is contained in:
jens
2009-01-02 16:22:12 +00:00
parent c574f7f0fd
commit a165d37bb7
1 changed files with 23 additions and 3 deletions
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lib/filter/src/fir_stage_sys.vhd
+23 -3
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@@ -43,10 +43,12 @@ Generic
nbits_out : integer := 12;
nbits_out_frac : integer := 12;
input_latency : integer := 1;
coef_latency : integer := 1;
pipe_latency : integer := 2
);
Port
(
rst : in std_logic;
clk : in std_logic;
x_in : in sfixed;
y_in : in sfixed;
@@ -66,8 +68,10 @@ subtype in_t is sfixed(shi(nbits_in, nbits_in_frac) downto slo(nbits_in, nbits_i
subtype out_t is sfixed(shi(nbits_out, nbits_out_frac) downto slo(nbits_out, nbits_out_frac));
type input_pipe_t is array (0 to input_latency) of in_t;
type coef_pipe_t is array (0 to coef_latency) of in_t;
type mult_pipe_t is array (0 to mult_latency) of out_t;
signal h_pipe : input_pipe_t;
signal x_pipe : input_pipe_t;
signal mult_pipe : mult_pipe_t;
@@ -84,12 +88,12 @@ begin
prod <= mult_pipe(mult_latency);
yin <= resize(y_in, yin);
hin <= resize(h_in, hin);
hin <= h_pipe(coef_latency);
xin <= x_pipe(input_latency);
x_out <= resize(xin, shi(nbits_out, nbits_out_frac), slo(nbits_out, nbits_out_frac));
------------------------------------------------------------
proc_in_reg: process(clk, x_in)
proc_xin: process(clk, x_in)
begin
x_pipe(0) <= resize(x_in, x_pipe(0));
if rising_edge(clk) then
@@ -100,6 +104,18 @@ begin
end process;
------------------------------------------------------------
proc_hin: process(clk, h_in)
begin
h_pipe(0) <= resize(h_in, h_pipe(0));
if rising_edge(clk) then
for i in 1 to coef_latency loop
h_pipe(i) <= h_pipe(i-1);
end loop;
end if;
end process;
------------------------------------------------------------
proc_pipe_reg: process(clk, xin, hin)
begin
@@ -117,7 +133,11 @@ begin
begin
if rising_edge(clk) then
yout := resize(yin + prod, yout, fixed_wrap, fixed_truncate);
y_out <= yout;
if rst = '1' then
y_out <= to_sfixed(0, yout);
else
y_out <= yout;
end if;
end if;
end process;