/
headerSelect.vhd
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/
headerSelect.vhd
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library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
use work.headerPkg.all;
use work.utilPkg.all;
use work.switchPkg.all;
entity headerSelect is
port (
headerIn : in headerArray(numPorts-1 downto 0);
selected : out std_logic_vector(numPorts-1 downto 0);
dataValid : out std_logic;
selectedRxPort : out portNr;
selectedAddr : out address
);
end entity headerSelect;
architecture rtl of headerSelect is
function selectHeaderWithPrio(headers:headerArray(numPorts-1 downto 0); searchedPrio:priority) return portNrWrapper is
variable rxPortNr : portNrWrapper;
begin
rxPortNr := (others => '0');
while rxPortNr<numPorts loop
if headers(wrappedPortNrToInteger(rxPortNr)).valid='1' then
if headers(wrappedPortNrToInteger(rxPortNr)).prio = searchedPrio then
return rxPortNr;
end if;
end if;
rxPortNr := rxPortNr + 1;
end loop;
return portNrUndefined;
end selectHeaderWithPrio;
function selectHeader(headers:headerArray(numPorts-1 downto 0)) return portNrWrapper is
variable rxPortNr : portNrWrapper;
variable pri : priority;
begin
pri := to_unsigned(numPriorities-1, priorityWidth);
loop
rxPortNr := selectHeaderWithPrio(headers,pri);
if rxPortNr /= portNrUndefined then
return rxPortNr;
end if;
exit when pri = to_unsigned(0, priorityWidth);
pri := pri-1;
end loop;
return portNrUndefined;
end selectHeader;
begin
nomem_output : process(headerIn)
variable rxPortNr : portNrWrapper;
begin
-- default assignments
selected <= (others => '0');
dataValid <= '0';
selectedRxPort <= (others => '-');
selectedAddr <= dontCareAddr;
rxPortNr := selectHeader(headerIn);
if rxPortNr /= portNrUndefined then
selected(wrappedPortNrToInteger(rxPortNr)) <= '1';
dataValid <= '1';
selectedRxPort <= toPortNr(rxPortNr);
selectedAddr <= headerIn(wrappedPortNrToInteger(rxPortNr)).addr;
end if;
end process nomem_output;
end architecture rtl;