A SENSORSYSTEMON CHIPFOR WIRELESSMICROSYSTEMS

encoder anda frequency shiftkeying (FSK) RF transmitter. Manyofthesystem blocks arefrompreRecentyearshaveseentherapiddevelopment of existing libraries, orhavebeenwritten andimported inan microsensor technology, system onchipdesign, wireless intellectual property (IP) blockform, thusthedesign technology andubiquitous computing. Whenassembled represents thefirst steps towards asensor system-on-chip. intoa complex microsystem thetechnologies become SENSORSYSTEMON CHIP powerful tools inmedical diagnostics, environmental monitoring andpersonal connectivity. Inthis paper we Figure 1showstheschematic oftheSOC.Thedesign describe thedemonstration ofasilicon chipthat hasall flowusedto createthe SOC was relatively theattributes required ofamicrosystem foruseinthese straightforward. Cadencetoolswereusedfor applications. Thedesign methodology wehaveemployed analogue/digital simulations andback-end design tasks isavariant ofthesystem onchipapproach whereby andSynopsys tools wereusedfordigital synthesis of manyintellectual property blocks areintegrated atahigh VHDL behavioural and register transfer level level inthedesign flow. Ourintellectual property blocks descriptions. Transistor-level orgate-level simulations include theanalogue sensorinstrumentation for wereusedtoverify that allfunctional blocks workedas temperature andpH,adatamultiplexing andconversion desired before chipassembly andimplementation. The module, adigital platform basedaround an8-bit micro- micro-controller block,including the hardware controller, dataencoding forspread-spectrum wireless architecture andthesoftware routines, wasverifled by transmission andaRFsection requiring veryfewoff-chip writing toaXILINXSPARTANII-FPGA followed by components. Thechiphasbeenfully evaluated and board-level testing toensure proper functionality before tested byconnection toexternal sensors. Eachblock has committing tosilicon. welldefined interfaces sothat theycanbeeasily reused Sensor interfaces infuture designs targeted todifferent applications. Thesystemoperates withpH (acidity/alkalin ity) and