| Line 176... |
Line 176... |
signal Strobe2xSN, Strobe2xSP : std_logic := '0';
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signal Strobe2xSN, Strobe2xSP : std_logic := '0';
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signal HistBufLen2xDN, HistBufLen2xDP : integer range 0 to HIST_BUF_LEN := 0;
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signal HistBufLen2xDN, HistBufLen2xDP : integer range 0 to HIST_BUF_LEN := 0;
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signal Candidate2xDN, Candidate2xDP : std_logic_vector(LOOK_AHEAD_LEN*8-1 downto 0) := (others => '0');
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signal Candidate2xDN, Candidate2xDP : std_logic_vector(LOOK_AHEAD_LEN*8-1 downto 0) := (others => '0');
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signal NextWrAdr2xDN, NextWrAdr2xDP : integer range 0 to LOOK_AHEAD_LEN := 0;
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signal NextWrAdr2xDN, NextWrAdr2xDP : integer range 0 to LOOK_AHEAD_LEN := 0;
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signal CandAddr2xDN, CandAddr2xDP : std_logic_vector(11 downto 0) := (others => '0');
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signal CandAddr2xDN, CandAddr2xDP : std_logic_vector(11 downto 0) := (others => '0');
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signal CandLen2xD : integer range 0 to LOOK_AHEAD_LEN;
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signal CandLen2xDN, CandLen2xDP : integer range 0 to LOOK_AHEAD_LEN;
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signal EndOfData2xSN, EndOfData2xSP : std_logic := '0';
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signal EndOfData2xSN, EndOfData2xSP : std_logic := '0';
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signal OffsetIntxD : integer range -HIST_BUF_LEN to HIST_BUF_LEN;
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signal OffsetIntxD : integer range -HIST_BUF_LEN to HIST_BUF_LEN;
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signal OffsetxD : std_logic_vector(11 downto 0);
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signal OffsetxD : std_logic_vector(11 downto 0);
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signal HashTableEntry2xDN, HashTableEntry2xDP : std_logic_vector(11 downto 0) := (others => '0');
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signal HashTableEntry2xDN, HashTableEntry2xDP : std_logic_vector(11 downto 0) := (others => '0');
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signal MaxCandLenxD : integer range 0 to LOOK_AHEAD_LEN;
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signal MaxCandLenxD : integer range 0 to LOOK_AHEAD_LEN;
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Line 398... |
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-- limit the max candidate length
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-- limit the max candidate length
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MaxCandLenxD <= LOOK_AHEAD_LEN;
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MaxCandLenxD <= LOOK_AHEAD_LEN;
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-- use a shifter to implement the last two bytes of the address
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-- use a shifter to implement the last two bytes of the address
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process (CandAddr1xDP, CandAddr2xDP, Candidate2xDP, HistBufLen1xDP,
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process (CandAddr1xDP, CandAddr2xDP, CandLen2xDP, Candidate2xDP,
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HistBufLen2xDP, HistBufOutxD, LookAheadBuf1xDP, LookAheadBuf2xDP,
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HistBufLen1xDP, HistBufLen2xDP, HistBufOutxD, LookAheadBuf1xDP,
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LookAheadLen1xDP, LookAheadLen2xDP, LookAheadPtr1xDP, MaxCandLenxD,
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LookAheadBuf2xDP, LookAheadLen1xDP, LookAheadLen2xDP,
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Strobe1xSP)
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LookAheadPtr1xDP, LookAheadPtr2xDP, MaxCandLenxD, Strobe1xSP)
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begin
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begin
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Candidate2xDN <= Candidate2xDP;
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Candidate2xDN <= Candidate2xDP;
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LookAheadBuf2xDN <= LookAheadBuf2xDP;
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LookAheadBuf2xDN <= LookAheadBuf2xDP;
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LookAheadLen2xDN <= LookAheadLen2xDP;
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LookAheadLen2xDN <= LookAheadLen2xDP;
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CandAddr2xDN <= CandAddr2xDP;
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CandAddr2xDN <= CandAddr2xDP;
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LookAheadPtr2xDN <= LookAheadPtr2xDP;
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HistBufLen2xDN <= HistBufLen2xDP;
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HistBufLen2xDN <= HistBufLen2xDP;
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CandLen2xDN <= CandLen2xDP;
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-- send data through pipeline when strobe is high
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if Strobe1xSP = '1' then
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if Strobe1xSP = '1' then
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-- note: the history buffer can't load data only from addresses where the
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-- last two bits are zero. If this was not the case we shift the candidate
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-- (which makes it shorter) to correct that
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case CandAddr1xDP(1 downto 0) is
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case CandAddr1xDP(1 downto 0) is
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when "00" => Candidate2xDN <= HistBufOutxD; -- no shifting
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when "00" => Candidate2xDN <= HistBufOutxD; -- no shifting
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CandLen2xD <= MaxCandLenxD;
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CandLen2xDN <= MaxCandLenxD;
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when "01" => Candidate2xDN <= x"00" & HistBufOutxD(LOOK_AHEAD_LEN*8-1 downto 8); -- shift one byte
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when "01" => Candidate2xDN <= x"00" & HistBufOutxD(LOOK_AHEAD_LEN*8-1 downto 8); -- shift one byte
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CandLen2xD <= MaxCandLenxD-1; -- we shifted one byte out -> candidate is one byte shorter
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CandLen2xDN <= MaxCandLenxD-1; -- we shifted one byte out -> candidate is one byte shorter
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when "10" => Candidate2xDN <= x"0000" & HistBufOutxD(LOOK_AHEAD_LEN*8-1 downto 16); -- shift 2 bytes
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when "10" => Candidate2xDN <= x"0000" & HistBufOutxD(LOOK_AHEAD_LEN*8-1 downto 16); -- shift 2 bytes
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CandLen2xD <= MaxCandLenxD-2;
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CandLen2xDN <= MaxCandLenxD-2;
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when "11" => Candidate2xDN <= x"000000" & HistBufOutxD(LOOK_AHEAD_LEN*8-1 downto 24); -- shift 3 bytes
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when "11" => Candidate2xDN <= x"000000" & HistBufOutxD(LOOK_AHEAD_LEN*8-1 downto 24); -- shift 3 bytes
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CandLen2xD <= MaxCandLenxD-3;
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CandLen2xDN <= MaxCandLenxD-3;
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when others => null;
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when others => null;
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end case;
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end case;
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LookAheadBuf2xDN <= LookAheadBuf1xDP;
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LookAheadBuf2xDN <= LookAheadBuf1xDP;
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LookAheadLen2xDN <= LookAheadLen1xDP;
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LookAheadLen2xDN <= LookAheadLen1xDP;
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Line 460... |
comparatorInst : comparator
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comparatorInst : comparator
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port map (
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port map (
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LookAheadxDI => CompLAIn3xD,
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LookAheadxDI => CompLAIn3xD,
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LookAheadLenxDI => LookAheadLen2xDP,
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LookAheadLenxDI => LookAheadLen2xDP,
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CandidatexDI => Candidate2xDP,
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CandidatexDI => Candidate2xDP,
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CandidateLenxDI => CandLen2xD,
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CandidateLenxDI => CandLen2xDP,
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MatchLenxDO => MatchLenxD);
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MatchLenxDO => MatchLenxD);
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-- calculate the offset
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-- calculate the offset
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process (CandAddr2xDP, LookAheadPtr2xDP, OffsetIntxD)
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process (CandAddr2xDP, LookAheadPtr2xDP, OffsetIntxD)
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begin
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begin
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| Line 572... |
Line 577... |
HistBufLen2xDP <= HistBufLen2xDN;
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HistBufLen2xDP <= HistBufLen2xDN;
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NextWrAdr2xDP <= NextWrAdr2xDN;
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NextWrAdr2xDP <= NextWrAdr2xDN;
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LookAheadPtr2xDP <= LookAheadPtr2xDN;
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LookAheadPtr2xDP <= LookAheadPtr2xDN;
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CandAddr2xDP <= CandAddr2xDN;
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CandAddr2xDP <= CandAddr2xDN;
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Candidate2xDP <= Candidate2xDN;
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Candidate2xDP <= Candidate2xDN;
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CandLen2xDP <= CandLen2xDN;
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HashTableEntry2xDP <= HashTableEntry2xDN;
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HashTableEntry2xDP <= HashTableEntry2xDN;
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EndOfData0xSP <= EndOfData0xSN;
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EndOfData0xSP <= EndOfData0xSN;
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EndOfData1xSP <= EndOfData1xSN;
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EndOfData1xSP <= EndOfData1xSN;
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EndOfData2xSP <= EndOfData2xSN;
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EndOfData2xSP <= EndOfData2xSN;
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Done3xSP <= Done3xSN;
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Done3xSP <= Done3xSN;
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