With　the　increasing　complexity　in　modem　circuit　designs,　the　6T&6TPPNN　circuits　have　become　popular　in　advanced　technologies　for　better　trade-offs　among　routability,　timing,　power　and　performance.　The　6TPPNN　cells　incur　great　challenges　to　layout　designs,　especially　the　legalization　problem　due　to　their　complex　minimum　width　(MW)　constraints　and　the　fragmentation　effect　(FE).　In　this　paper,　we　address　the　mixed　6T&6TPPNN　cell　legalization　problem　considering　both　MW　constraints　and　FE　issues.　Given　a　global　placement　result,　we　first　align　all　cells　to　the　correct　rows/half-rows　that　satisfy　the　VDD/VSS　alignment　constraints,　and　then　propose　a　clustering-based　MW　constraints　solving　method　to　eliminate　all　the　MW　violations.　After　that,　we　formulate　the　legalization　problem　with　MW　constraints　as　a　quadratic　programming　(QP)　problem,　which　not　only　satisfies　the　MW　constraints,　but　also　avoid　causing　excessive　dead　spaces.　Finally,　we　integrate　the　FE　issues　into　the　formulated　MW-aware　QP　model,　and　adopt　the　modulus-based　matrix　splitting　iteration　method　(MMSIM)　to　solve　the　mathematical　model　effectively　and　efficiently.　Experimental　results　show　that　our　algorithm　can　resolve　all　MW　constraints　and　mitigate　the　half-row　fragmentation　effect　without　any　extra　area　overhead　in　a　reasonable　time.