MODASC: ASIC for mobile data acquisition systems using satellite communications

MODASC: ASIC o Mobile Da a Acquisi ion Sys ems using Sa elli e Communica ions J.M. Que o, L.G. F anquelo, C.L. Jane , J.G. O ega and S. To al Dp o. de Ingenie ´ıaElec ´ onica EscuelaSupe io de Ingenie os, A da. ReinaMe cedes s/n, Se illa–41012(SPAIN) Tel.: +34(9)5 45568 57 Fax: +34 (9)5 455 6849 e–mail: [email p o ec ed] F. Ma ´ınand J. L´ opez SAINSEL Manuel VelascoPando s/n, Se illa(SPAIN) Tel.: +34(9)5 45736 91 Fax: +34 (9)5 457 9362 Abs ac — MODASC is anASIC ha pe o ms widea eamobileda a acquisi ionusingsa elli ecommunica ion o p o ideglobalco e age. This ci cui p o ides wo ope a ion modes: an au onomous mode, ha pe iodicallyes ablishesconnec ionwi h hecon olcen e ,andasla e mode, wo king as a pe iphe al connec ed o a gene al pu pose mic o con olle . This expe imen has been ealized unde FUSE special ac ionin collabo a ionwi hSAINSEL. I. INTRODUCTION Mos da a acquisi ion sys ems make use o com- munica ion channels o send cap u ed da a o he con ol cen e . These communica ion channels a e usually adio links, local compu e ne wo ks o dedica ed elephone lines. The selec ion o hemos sui ablecommunica ion channel is de e - mined by aking in o accoun applica ion pa ame- e s,suchasdis ance,ins alla ionand ansmission cos s, liabili y, ::: All p e iously men ioned com- munica ion channel al e na i es a e used o ixed ins alla ions o mobile s a ionsin a local a ea. Bu when wide a ea da aacquisi ion is equi ed, sa el- li e communica ion is he mos alid al e na i e because i p o ides global co e age. In his pape we p esen an ASIC designed o acqui e da a and send i o a con ol cen e ia Inma sa . This ci cui p o ides wo ope a ion modes: an au onomous mode, ha pe iodically es- ablishes connec ion wi h he con ol cen e , and a sla e mode, wo king as a pe iphe al connec ed oa gene al pu pose mic ocon olle . II. FUNCTIONAL DESCRIPTION The unc ionali yo hisci cui canbesumma ized as emo eda aacquisi ionand communica ionus- ing sa elli elinks. Asi hasbeenmen ionedabo e, hisci cui p esen wo di e en ope a ion modes: an au onomous mode and a sla e mode. In he i s mode, he ci cui uses he Da a Com- munica ion Equipmen (DTE) GALAXY-C/GPS omTRIMBLE [1]. This anscei e usesInma sa S anda d-C sa elli e communica ion p o ocol and also ecei es signal acco ding o GPS s anda d. The DTE/ASIC physical in e ace is o e an RS- 232 link. In he second mode, his connec ion and i s p o- ocol a e no longe needed, al hough hey can be easily implemen ed using one o he 5 a ailable se ial channels implemen ed in MODASC. The mode selec ion is de e mined by pin named CONFIG,whe e0and1indica esau onomousand sla e modes espec i ely. As bo h modes a e in- dependen , bellow hey a e explained in di e en sec ions. A. Au onomousMode In his mode MODASC cap u es en i onmen- al da a and also de e mines i s posi ion using GPS. Acco ding o a p ede e mined schedule, MODASCwai sun il hecon olcen e es ablishes a connec ion, sending que ies o de e mine ASIC p esen s a us. In igu e 1 a block diag am o au onomous mode is shown. In his mode, he mos c i ical issue is o ensu e powe supply o gua an ee p ope op- e a ion and loca ion o he sys em. The e o e, en- e gy consump ion minimiza ion should be aken. MODASCin e nallys o essenso in o ma ionand ecei esGPSposi ion om he anscei e . All his da a is pe iodically sen o he con ol cen e . The unc ionali y o he ci cui is comple ed wi h TRANSCEPTOR CAD CONTROL CAD CAD NBAT RS-232-C LD1 LD2 SETTTRA1 SETTRA2 MAE BUZ SETFLSH CONFIG=0 SNAP . . . . NBAT POSITION SPEED COURSE REAL TIME CLOCK TRANSCEPTOR CRC DES COMMUNICATION FREQUENCY DIVIDER POWER SUPPLY CONTROL PROTOCOL ARITMETIC UNIT MEMORY SENSOR SENSOR MEASURE MEASURE EPROM MEMORY RAM ADDRESS BUS DATA BUS BLOCK SURVEILLANCE ANTENNA Figu e 1: ASIC unc ional diag am in au onomousmode iola ion senso s, op ical and acous ical signals o indica e unc ionals a us,con olblock,a i hme ic uni , equency di ide and in e nal con igu a ion egis e s. MODASC is connec ed o he GALAXY anscei e using RS- 232-C. In o de o achie e maximum compa ibil- i ywi ho he anscei e s, hecommunica ionbe- weenASIC and GALAXY u ilizesSTANDARD-C Inma sa P o ocol when possible. The Communi- ca ion Module is de o ed o his communica ion p o ocol. To achie e da a p i acy, s anda d enc yp ion al- go i hm (DES)[2] is implemen edin MODASC. To e i y da ain eg i y, CRC code is added a heend o e e y message. The Powe Supply Module deals wi h powe con- sump ion, ac i a ing pe iphe als only when i is needed. The ac i a ion schedule can be de e - mined using p og ammable ime s. This mod- ule also supe ises ba e y ol age le el. When his ol age le el is bellow a p ede ined e e ence (50%), MODASC begins wo king in ene gy sa ing mode. When in his mode, i s unc ionali y is e- duced o p o ide communica ionwi h he con ol cen e . The Analog Signal Acquisi ion Module cap u es en i onmen alanalogda a. Eigh en-bi analog o digi al s ochas ic con e e s [3] a e implemen ed. The main ad an ageo hesecon e e s is ha use pu ely digi al echnology, hus dec easing manu- ac u ing cos s. A eal- imeclockisincluded ode e minecommu- nica ion pe iods. This clock is upda e whene e ASIC ecei es GPS ime. The Global Con ol Module de e mines he global unc ionali yo hesys em,includingaccess osys- em buses. The kind o messages used in INMARSAT-C p o- ocolis he’S o e&Fo wa d’class,chosenbecause o i s high eliabili y and accep able ansmission cos . Fo debugging acili ies, an auxilia y se ial po is connec ed o he se ial po de o ed o anscei e communica ion, as i is shown in igu e 2. This way, when CONFIG is equal o 0 (au onomous mode), he auxilia y se ial po ecei es all mes- sages ha a e ansmi ed be ween anscei e and ASIC, and i can di ec ly send da a o he anscei e obecon igu ed. Insla emode(CON- UART 2 UART 1 GALAXY (TRIMBLE) TERMINAL CONFIG CONFIG 0 1 0 1 ASIC 0 RS-232-C RS-232-C ADAPTER ADAPTER Figu e 2: ASIC-T anscei e p o ocol moni o ing in au onomousmode FIG=1) se ial po s a e wo king independen ly. B. Sla eMode In hismode MODASC wo ks as a pe iphe al o a s anda d mic op ocesso . In igu e 3 a block dia- g am co esponding o he sla e mode is shown. An 8-bi da a bus, 6-bi add ess bus, R=  W and  CS a e mic ocon olle ’s signals o access ASIC da a. In his mode, MODASC p o ides 5 se ialcommu- C A/D C A/D C A/D C A/D Canal 0 Canal 1 Canal 2 Canal 4 Canal 3 RxD0 TxD0 RxD1 TxD1 RxD2 TxD2 RxD3 TxD3 TxD4 RxD4 Rec. Bu e T ansm. Bu e Rec. Bu e T ansm. Bu e Rec. Bu e T ansm. Bu e Rec. Bu e T ansm. Bu e Rec. Bu e T ansm. Bu e Wa ch - Dog WD C A/D C A/D C A/D C A/D eloj P og amacion R/W ED7 ED5 ED6 ED4 ED3 ED2 ED1 ED0 SD7 SD5 SD6 SD4 SD3 SD1 SD0 WDRESET SD2 ECA7SE7 SE6 ECA6 SE5 ECA5 ECA4 ECA3SE4 SE3 SE2 ECA2 ECA1SE1 SE0 ECA0 ADB 5:0 DB 7:0 CS INT SCL SDA I2C RDD RDI cla e DES DATA BUS ADDRESS BUS REGISTERS STATUS AND MASK CONFIGURATION REGISTERS STATUS MASKS REAL TIME CLOCK BAUD RATE GENERATOR IRQ INTERRUPT CONTROLLER Figu e 3: ASIC unc ional diag am in sla e mode nica ion po s. They manage 8 da a, one s a and one s op bi s. Whene e an UART ecei es one da a by e, i gene a es an ex e nal in e up ion. Simila ly, when one da a by e is w i en in he ansmission egis e , i is au oma ically ansmi - ed. When his bu e emp ies, he co esponding s a e lag is ac i a ed. The e exis a mask egis e odeac i a ein e up ions,andane o egis e o indica e ame e o s. Ano he communica ion block implemen s a sim- pli ied e sion o an I 2 C bus [4]. This is a syn- ch onous se ial communica ion channel, ha u i- lizes only wo lines: a bidi ec ional da a line and a synch oniza ion clock line. In ou app oach, his mode isconside ed o be mas e espec o pe iph- e alci cui s ha wo kassla eswhen heya e con- nec ed o his po . Communica ion ames a e composed o 7-bi ad- d ess,aR/Wbi ,oneby eo da a,andan ecep ion acknowledge bi (see igu e 4). The synch oniza- ion clock equency is 100 K bi s/s. SDA SCL 12 789 ACK Acknoeledgemen 123 789 Acknoeledgemen STOPSTART Figu e 4: I 2 C bus da a ans e Signal iming and elec ical ea u es comply spec- i ica ions gi en in [4]. Ex e nal con ol o I 2 C bus is ealized by w i ing and eading ope a ions o co esponding ou pu and inpu da a egis e s. A ailable s a us egis e allows o con ol o hisblock. Bo h in e up and polling managemen o his po is possible. A Wa ch-Dog ci cui has been included in ASIC unc ionali y o p e en mic ocon olle om be- ing blocked. ASIC unc ionali y is comple ed wi h 8 inpu and 8 ou pu digi al signals, 8 Analog o digi al con- e e s based on s ochas ic logic [3] as i is d awn in igu e 5, a eal ime clock, and DES block Vo Vi ASIC SUCESIVE REGISTER APPROXIMATION DIGITAL VALUE RANDOM NUMBER GENERATOR CDE Figu e 5: Block Diag am o an analog o digi al con e e based on s ochas ic logic III. IMPLEMENTATION C i ical blocks, such as Inma sa -C p o ocol, ha e been simula ed in C language. Now, he hole sys em i s being desc ibed in beha io al language (VERILOG [5]). The ASIC will be designed using CADENCE DESIGN FRAMEWORK II. The ASIC has a es ima ed a ea o 50 mm 2using ES2 ECPD07 S anda Cell echnologyandPLCC-84packagehas been selec ed. REFERENCES [1] GALAXY-C/GPSUse s Manual. TRIMBLE. 1995 [2] A.S. Tannenbaum Compu e Ne wo ks. P en ice-Hall In e na- ional. 1989. [3] J.G. O ega, C.L. Jane , J.M. Que o and L.G. F anquelo. “Analog o Digi al and Digi al o Analog Con e sion Based on S ochas ic Logic” . P oceedings IECON’95. [4] Philips Semiconduc o s 80C51-Based8-Bi Mic ocon olle s [5] Ve ilog-XL.Re e enceManual, ol1,2,3 .CadenceDesignSys ems, Inc.