Along　with　device　scaling,　the　drain-to-drain　abutment　(DDA)　and　fence　region　constraints　arise　as　emerging　challenges　in　modern　circuit　designs,　incurring　additional　difficulties,　especially　for　designs　with　mixed-cell-height　standard　cells　which　have　prevailed　in　advanced　technology.　This　article　presents　the　first　work　to　address　the　mixed-cell-height　placement　problem　considering　the　DDA　and　fence　region　constraints　from　post-global　placement　throughout　the　detailed　placement.　Our　algorithm　consists　of　three　major　stages:　1)　preprocessing;　2)　legalization;　and　3)　detailed　placement.　At　the　preprocessing　stage,　we　align　cells　to　the　desired　rows　that　meet　the　region　constraint,　considering　the　total　cell　displacement　and　the　distribution　ratio　of　source　nodes　to　drain　nodes　simultaneously.　After　deciding　the　cell　ordering　of　every　row,　we　first　propose　an　interval　concept　to　handle　fixed　macros　and　fence　regions　and　then　apply　the　robust　modulus-based　matrix　splitting　iteration　method　to　remove　all　cell　overlaps　with　minimized　total　displacement　at　the　legalization　stage.　For　detailed　placement,　unlike　the　existing　works　that　can　handle　the　DDA　constraint　only　for　single　rows,　we　propose　a　satisfiability-based　approach　that　considers　the　whole　layout　to　fix　the　DDA　violations　more　effectively.　Besides,　we　further　present　an　integer　linear　program　(ILP)-based　method　to　optimize　the　cell　displacement　without　increasing　the　DDA　violations.　Compared　with　a　shortest-path　method,　experimental　results　show　that　our　proposed　algorithm　can　significantly　reduce　cell　violations,　average　cell　displacement,　and　maximum　cell　displacement,　in　a　comparable　runtime.