This　paper　forwards　a　low　power　grating　detection　chip　(EYAS)　on　length　and　angle　precision　measurement.　Traditional　grating　detection　method,　such　as　resister　chain　divide　or　phase　locked　divide　circuit　are　difficult　to　design　and　tune.　The　need　of　an　additional　CPU　for　control　and　display　makes　these　methods＇　implementation　more　complex　and　costly.　Traditional　methods　also　suffer　low　sampling　speed　for　the　complex　divide　circuit　scheme　and　CPU　software　compensation.　EYAS　is　an　application　specific　integrated　circuit　(ASIC).　It　integrates　micro　controller　unit　(MCU),　power　management　unit　(PMU),　LCD　controller,　Keyboard　interface,　grating　detection　unit　and　other　peripherals.　Working　at　10MHz,　EYAS　can　afford　5MHz　internal　sampling　rate　and　can　handle　1.25MHz　orthogonal　signal　from　grating　sensor.　With　a　simple　control　interface　by　keyboard,　sensor　parameter,　data　processing　and　system　working　mode　can　be　configured.　Two　LCD　controllers　can　adapt　to　dot　array　LCD　or　segment　bit　LCD,　which　comprised　output　interface.　PMU　alters　system　between　working　and　standby　mode　by　clock　gating　technique　to　save　power.　EYAS　in　test　mode　(system　action　are　more　frequently　than　real　world　use)　consumes　0.9mw,　while　0.2mw　in　real　world　use.　EYAS　achieved　the　whole　grating　detection　system　function,　high-speed　orthogonal　signal　handling　in　a　single　chip　with　very　low　power　consumption.