Variaus e nergeric particles in rh e space radia~ (íon environmenr C. 1.11 inreracr with silicon (Q cause undcsirable effects. When a single heavy ion strikes sili col1, ir loses irs energy by crea rin g frc e elcc rro n-hole pairs, resu]r ing in a dense ionized rrack in the local region. Protons and neurrons can cause nuclear imcracrions wh en pass ing through rhe material. The rccail a150 prod uces ionizar ian , which generates a tran sic nt current pulse (har can cau se an upset wh en ilHe rprered as a signal in eh e circuic. With technology sca ling imo deepsubmi cron dimens ions, the efreccs of energetic particle h its become a co nce rn even at sea levei, wh ere rhe major hi gh-e nergy radiarion source is atmospheric neurrons and prorons.A singlc partide can hit eirh er the sequentiaJ logic ar rhe combinarionallogic in th e silicon. When an energetic partide strikes one of a memory cell 's sens itive sires, the effect ca n produce an inversion in th e srored value-in oeher words, a bit Aip in rhe memory ceU. This is called a single-evem upset (SEU) .2 Whe n an energeri c particle hits a se nsitive site in rhe com bi national logic block, ir also generates a rransiem currem pulse. This phenomenon is
called a single-evem rran sieIH (SET).3 ForPublished by the IEEE Computer Society combinational logi c bloc ks with reg istered outputs, the SET can evemually appear at rh e inpur of th e Aip-Aops placed at the com b inationallogic ourpurs, u nless t he induced rransie m pulse is e it he r 10gica1l y or electricall y masked by t he logic inpurs. If interpreted as a valid signal in che register inpU[, rhi s SET ca n cause an in co rrect valu e to be srored in th e register, provoking a soft crro r.Conrinuous rechno logy evo lu ri o n and small e r rransiswr featu res have made so ft errors on dev ices more frequ ento D etecein g soft e rrors in combinarional a nd sequentia l logic is criti cai for avoiding erro rs in the c ircuir applicarion. Howeve r, t his eas k is co mplex becau se the intern a i ci rcu ir signals a re decrcasing to che same order of magni tud e as the transienr currenrs,generated by cha rgedpartide strikes.Researchers have proposed a bu ilr-in currem senso r (BIC S) connected to t he powe r lines for moniroring on-chip current variati ons provoked by pcrmanent faules, such as stu ckar fallles, a nd by soft erro rs in memoryelements.-4,5 However, to rh e besr of our knowledge. no one has yer proposed a BI CSbased method for derecring SETs in combinafional lo gic, a nd (his iss ue is gain ing importance in new rechn ologies. We propose an approach for using BI CS to derect transiem