chaitanya.531
Member level 1
hi
plz help
when i synthesis vhdl
the following warnings occurs
WARNING:Xst:2170 - Unit rc5round : the following signal(s) form a combinatorial loop: rc5round_ao<8>_cyo, ao<17>, c1/N27, m2<17>, rc5round_ao<5>_cyo, rc5round_ao<12>_cyo, rc5round_ao<1>_cyo, rc5round_ao<4>_cyo, m3<0>, rc5round_ao<3>_cyo, d1/r<0>, rc5round_ao<9>_cyo, rc5round_ao<11>_cyo, rc5round_ao<10>_cyo, c1/N19, rc5round_ao<0>_cyo, rc5round_ao<13>_cyo, rc5round_ao<6>_cyo, rc5round_ao<14>_cyo, c1/N31, rc5round_ao<2>_cyo, c1/do<0>_map1720, c1/N1, m4<0>, cs<0>, rc5round_ao<16>_cyo, rc5round_ao<7>_cyo, rc5round_ao<15>_cyo.
WARNING:Xst:2170 - Unit rc5round : the following signal(s) form a combinatorial loop: m4<1>, c1/N22, cs<17>, c1/N227, cs<1>, c1/do<2>_map1696, rc5round_ao<17>_cyo, cs<2>, ao<18>, ao<2>, m2<18>, m3<2>, c1/N152, m2<2>, m3<17>, c1/N88, c1/N219, c1/do<17>_map1468, c1/N215, ao<19>, c1/N225, m2<19>, c1/N91, c1/N86, c1/N231, c1/N83, c1/N184, rc5round_ao<18>_cyo, N5, c1/do<1>_map1708, d1/r<1>.
WARNING:Xst:2170 - Unit rc5round : the following signal(s) form a combinatorial loop: c1/N159, ao<21>, c1/N229, m2<21>, m3<19>, c1/do<3>_map1672, c1/N69, c1/N71, c1/N133, d1/r<3>, c1/do<19>_map1408, rc5round_ao<19>_cyo, c1/do<4>_map1648, m4<3>, cs<19>, cs<3>, c1/N158, c1/N73, c1/N239, c1/N156, c1/N136, cs<4>, ao<20>, ao<4>, c1/N235, m2<20>, m2<4>, c1/N30, rc5round_ao<20>_cyo, m3<4>, N7.
WARNING:Xst:2170 - Unit rc5round : the following signal(s) form a combinatorial loop: m4<5>, cs<21>, cs<5>, c1/N243, c1/do<6>_map1600, d1/r<5>, c1/N150, c1/N29, c1/N182, N9, c1/N137, c1/do<5>_map1624, cs<6>, ao<22>, c1/N247, ao<6>, m2<22>, c1/N26, m2<6>, c1/do<21>_map1516, rc5round_ao<22>_cyo, ao<23>, m2<23>, c1/N151, c1/N237, m3<6>, c1/N148, m3<21>, c1/N197, c1/N199, rc5round_ao<21>_cyo.
WARNING:Xst:2170 - Unit rc5round : the following signal(s) form a combinatorial loop: ao<25>, c1/N192, c1/N55, m2<25>, c1/N135, N11, c1/N85, c1/N194, rc5round_ao<23>_cyo, d1/r<7>, c1/N212, c1/N245, c1/N28, m4<7>, cs<23>, cs<7>, c1/N254, rc5round_ao<24>_cyo, m3<8>, c1/N251, c1/do<7>_map1576, c1/N207, cs<8>, ao<24>, c1/do<8>_map1552, ao<8>, m2<24>, m2<8>, c1/do<23>_map1564, m3<23>, c1/N87.
WARNING:Xst:2170 - Unit rc5round : the following signal(s) form a combinatorial loop: c1/N74, c1/N62, cs<25>, cs<9>, c1/N255, c1/N60, c1/N70, d1/r<9>, c1/do<9>_map1528, cs<10>, c1/N21, ao<26>, ao<10>, m2<26>, m2<10>, rc5round_ao<25>_cyo, c1/do<10>_map1504, c1/N84, ao<27>, c1/N90, m2<27>, c1/N76, c1/N94, c1/do<25>_map1432, m3<10>, c1/N18, m3<25>, rc5round_ao<26>_cyo, N13, c1/N25, m4<9>.
WARNING:Xst:2170 - Unit rc5round : the following signal(s) form a combinatorial loop: c1/N160, ao<29>, m2<29>, c1/N24, d1/r<11>, c1/do<12>_map1360, N15, c1/N157, c1/N118, c1/N51, c1/N153, rc5round_ao<27>_cyo, c1/N96, c1/N145, m4<11>, rc5round_ao<28>_cyo, cs<27>, cs<11>, c1/do<11>_map1480, c1/N116, m3<27>, c1/N143, cs<12>, c1/N114, m3<12>, ao<28>, ao<12>, m2<28>, m2<12>, c1/N149, c1/do<27>_map1456.
WARNING:Xst:2170 - Unit rc5round : the following signal(s) form a combinatorial loop: cs<29>, rc5round_ao<29>_cyo, cs<13>, c1/N189, c1/N175, m3<29>, c1/do<29>_map1660, c1/do<14>_map1588, c1/N162, c1/N198, c1/N23, c1/do<13>_map1372, c1/N172, c1/N75, cs<14>, ao<30>, ao<14>, m2<30>, m2<14>, c1/N48, c1/N50, ao<31>, c1/N20, m2<31>, c1/N193, c1/N187, rc5round_ao<30>_cyo, m3<14>, N17, d1/r<13>, m4<13>.
WARNING:Xst:2170 - Unit rc5round : the following signal(s) form a combinatorial loop: c1/N203, c1/N210, c1/N138, m3<16>, N19, c1/do<15>_map1384, c1/N213, c1/N102, c1/N105, d1/r<15>, m4<15>, cs<15>, c1/N140, c1/N200, cs<16>, c1/do<16>_map1402, ao<16>, m2<16>.
what is meaning of the following signal(s) form a combinatorial loop:
how to rectify this error
plz help
when i synthesis vhdl
the following warnings occurs
WARNING:Xst:2170 - Unit rc5round : the following signal(s) form a combinatorial loop: rc5round_ao<8>_cyo, ao<17>, c1/N27, m2<17>, rc5round_ao<5>_cyo, rc5round_ao<12>_cyo, rc5round_ao<1>_cyo, rc5round_ao<4>_cyo, m3<0>, rc5round_ao<3>_cyo, d1/r<0>, rc5round_ao<9>_cyo, rc5round_ao<11>_cyo, rc5round_ao<10>_cyo, c1/N19, rc5round_ao<0>_cyo, rc5round_ao<13>_cyo, rc5round_ao<6>_cyo, rc5round_ao<14>_cyo, c1/N31, rc5round_ao<2>_cyo, c1/do<0>_map1720, c1/N1, m4<0>, cs<0>, rc5round_ao<16>_cyo, rc5round_ao<7>_cyo, rc5round_ao<15>_cyo.
WARNING:Xst:2170 - Unit rc5round : the following signal(s) form a combinatorial loop: m4<1>, c1/N22, cs<17>, c1/N227, cs<1>, c1/do<2>_map1696, rc5round_ao<17>_cyo, cs<2>, ao<18>, ao<2>, m2<18>, m3<2>, c1/N152, m2<2>, m3<17>, c1/N88, c1/N219, c1/do<17>_map1468, c1/N215, ao<19>, c1/N225, m2<19>, c1/N91, c1/N86, c1/N231, c1/N83, c1/N184, rc5round_ao<18>_cyo, N5, c1/do<1>_map1708, d1/r<1>.
WARNING:Xst:2170 - Unit rc5round : the following signal(s) form a combinatorial loop: c1/N159, ao<21>, c1/N229, m2<21>, m3<19>, c1/do<3>_map1672, c1/N69, c1/N71, c1/N133, d1/r<3>, c1/do<19>_map1408, rc5round_ao<19>_cyo, c1/do<4>_map1648, m4<3>, cs<19>, cs<3>, c1/N158, c1/N73, c1/N239, c1/N156, c1/N136, cs<4>, ao<20>, ao<4>, c1/N235, m2<20>, m2<4>, c1/N30, rc5round_ao<20>_cyo, m3<4>, N7.
WARNING:Xst:2170 - Unit rc5round : the following signal(s) form a combinatorial loop: m4<5>, cs<21>, cs<5>, c1/N243, c1/do<6>_map1600, d1/r<5>, c1/N150, c1/N29, c1/N182, N9, c1/N137, c1/do<5>_map1624, cs<6>, ao<22>, c1/N247, ao<6>, m2<22>, c1/N26, m2<6>, c1/do<21>_map1516, rc5round_ao<22>_cyo, ao<23>, m2<23>, c1/N151, c1/N237, m3<6>, c1/N148, m3<21>, c1/N197, c1/N199, rc5round_ao<21>_cyo.
WARNING:Xst:2170 - Unit rc5round : the following signal(s) form a combinatorial loop: ao<25>, c1/N192, c1/N55, m2<25>, c1/N135, N11, c1/N85, c1/N194, rc5round_ao<23>_cyo, d1/r<7>, c1/N212, c1/N245, c1/N28, m4<7>, cs<23>, cs<7>, c1/N254, rc5round_ao<24>_cyo, m3<8>, c1/N251, c1/do<7>_map1576, c1/N207, cs<8>, ao<24>, c1/do<8>_map1552, ao<8>, m2<24>, m2<8>, c1/do<23>_map1564, m3<23>, c1/N87.
WARNING:Xst:2170 - Unit rc5round : the following signal(s) form a combinatorial loop: c1/N74, c1/N62, cs<25>, cs<9>, c1/N255, c1/N60, c1/N70, d1/r<9>, c1/do<9>_map1528, cs<10>, c1/N21, ao<26>, ao<10>, m2<26>, m2<10>, rc5round_ao<25>_cyo, c1/do<10>_map1504, c1/N84, ao<27>, c1/N90, m2<27>, c1/N76, c1/N94, c1/do<25>_map1432, m3<10>, c1/N18, m3<25>, rc5round_ao<26>_cyo, N13, c1/N25, m4<9>.
WARNING:Xst:2170 - Unit rc5round : the following signal(s) form a combinatorial loop: c1/N160, ao<29>, m2<29>, c1/N24, d1/r<11>, c1/do<12>_map1360, N15, c1/N157, c1/N118, c1/N51, c1/N153, rc5round_ao<27>_cyo, c1/N96, c1/N145, m4<11>, rc5round_ao<28>_cyo, cs<27>, cs<11>, c1/do<11>_map1480, c1/N116, m3<27>, c1/N143, cs<12>, c1/N114, m3<12>, ao<28>, ao<12>, m2<28>, m2<12>, c1/N149, c1/do<27>_map1456.
WARNING:Xst:2170 - Unit rc5round : the following signal(s) form a combinatorial loop: cs<29>, rc5round_ao<29>_cyo, cs<13>, c1/N189, c1/N175, m3<29>, c1/do<29>_map1660, c1/do<14>_map1588, c1/N162, c1/N198, c1/N23, c1/do<13>_map1372, c1/N172, c1/N75, cs<14>, ao<30>, ao<14>, m2<30>, m2<14>, c1/N48, c1/N50, ao<31>, c1/N20, m2<31>, c1/N193, c1/N187, rc5round_ao<30>_cyo, m3<14>, N17, d1/r<13>, m4<13>.
WARNING:Xst:2170 - Unit rc5round : the following signal(s) form a combinatorial loop: c1/N203, c1/N210, c1/N138, m3<16>, N19, c1/do<15>_map1384, c1/N213, c1/N102, c1/N105, d1/r<15>, m4<15>, cs<15>, c1/N140, c1/N200, cs<16>, c1/do<16>_map1402, ao<16>, m2<16>.
what is meaning of the following signal(s) form a combinatorial loop:
how to rectify this error