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.