AAssssuurraannccee ooff CCoommpplleexx EElleeccttrroonniiccss WWhhaatt ppaatthh ddoo wwee ttaakkee?? Abstract Many of the methods used to develop software bare a close resemblance to Complex Electronics (CE) development. CE are now programmed to perform tasks that were previously handled in software, such as communication protocols. For instance, Field Programmable Gate Arrays (FPGAs) can have over a million logic gates while system-on-chip (SOC) devices can combine a microprocessor, input and output channels, and sometimes an FPGA for programmability. With this increased intricacy, the possibility of “software-like” bugs such as incorrect design, logic, and unexpected interactions within the logic is great. Since CE devices are obscuring the hardware/software boundary, we propose that mature software methodologies may be utilized with slight modifications to develop these devices. By using standardized S/W Engineering methods such as checklists, missing requirements and “bugs” can be detected earlier in the development cycle, thus creating a development process for CE that will be easily maintained and configurable based on the device used. Richard Plastow
https://ntrs.nasa.gov/search.jsp?R=20070007336 2020-07-14T18:29:56+00:00Z
Ass
ura
nce
of
Com
plex
A
ssu
ran
ce o
f C
ompl
ex
Elec
tron
ics
Elec
tron
ics
Wh
at p
ath
do
we
take
?W
hat
pat
h d
o w
e ta
ke?
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
2
Th
e Q
uan
dar
y
Pro
gram
mab
le L
ogic
dev
ices
are
blu
rring
the
hard
war
e / s
oftw
are
boun
dary
. It i
s no
w
com
mon
for C
ompl
ex E
lect
roni
cs (C
E)
devi
ces
to h
ave
over
one
milli
on g
ates
and
ev
en a
bui
lt in
mic
ropr
oces
sor.
Thes
e de
vice
s ar
e be
ing
used
to re
plac
e so
ftwar
e in
m
any
criti
cal a
pplic
atio
ns.
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
3
Lets
take
a lo
ok
Hardware
•Pro
gram
med
•Eas
ily c
hang
ed•C
an “
do a
nyth
ing”
•Can
not b
e 10
0%, e
xhau
stiv
ely
test
ed
BIO
S/bo
otst
rap
Ope
ratin
g sy
stem
App
licat
ions
Soft
war
e
Softw
are
resi
ding
in n
on-v
olat
ile
stor
age
Firm
war
e •Off
-the-
shel
f com
pone
nts
•Exh
aust
ivel
y Te
sted
by
Ven
dor
ICs
Mic
ropr
oces
sor
A/D
, D/A
Sens
ors
Ele
ctro
nic
Har
dwar
e
•Spe
cial
pur
pose
com
pute
r (pr
oces
s con
trol)
•Use
s Lad
der L
ogic
, oth
er la
ngua
ges f
or
prog
ram
min
g
Prog
ram
mab
le L
ogic
Con
trol
lers
SOC
R
econ
fig.
Com
putin
g•D
esig
ned
with
HD
L•C
ompi
led/
Prog
ram
med
•May
be
repr
ogra
mm
able
in th
e fie
ld•C
anno
t be
100%
, exh
aust
ivel
y te
sted
FPG
AC
PLD
PAL
ASI
C
Prog
ram
mab
le L
ogic
Dev
ices
Software
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
4
How
do
they
com
pare
?
CE A
sync
hron
ous
Cos
tly to
cha
nge
No
upda
tes
can
be d
one
in o
pera
tion
No
curr
ent s
tand
ards
Reu
sabl
eC
an n
ot b
e 10
0%
test
ed
Sof
twar
eS
ynch
rono
usE
asy
to c
hang
eP
atch
es c
an b
e do
ne in
op
erat
ion
Hav
e de
fined
sta
ndar
dsR
eusa
ble
Can
not
be
100%
te
sted
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
5
Conc
erns
and
Issu
es
AS
ICs
and
FPG
As
have
bee
n us
ed to
avo
id th
e rig
ors
of
the
softw
are
appr
oval
pro
cess
. (F
AA
DO
-254
)C
ompl
ex E
lect
roni
c de
vice
s ar
e de
sign
ed a
nd
prog
ram
med
by
engi
neer
s, o
ften
with
out q
ualit
y as
sura
nce
over
sigh
t or c
onfig
urat
ion
man
agem
ent
cont
rol o
f the
des
igns
. In
addi
tion,
the
deve
lopm
ent
proc
ess
may
not
be
wel
l def
ined
or f
ollo
wed
. H
igh-
leve
l lan
guag
es (e
.g. C
, C++
) are
now
bei
ng u
sed
to d
efin
e co
mpl
ex e
lect
roni
c de
sign
s (in
who
le o
r in
part)
.C
ompl
ex fu
nctio
nalit
y ca
nnot
be
com
plet
ely
sim
ulat
ed,
nor t
he re
sulti
ng c
hip
com
plet
ely
test
ed.
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
6
Wha
t is t
o be
don
e?
Sof
twar
e an
d C
ompl
ex E
lect
roni
cs h
ave
man
y th
ings
in c
omm
on.
Bot
h ha
ve a
Qua
lity
Ass
uran
ce p
rogr
amB
oth
Sha
re a
com
mon
dev
elop
men
t pro
cess
Sin
ce th
e C
ompl
ex E
lect
roni
cs d
evic
e is
a b
lend
, w
hy n
ot u
se th
e be
st o
f bot
h as
sura
nce
wor
lds?
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
7
Com
mon
ality
in D
evelo
pmen
t pro
cess
Sof
twar
eP
lann
ing
Req
uire
men
tsD
esig
nC
ode
Test
Ope
ratio
ns
CE P
lann
ing
Req
uire
men
tsD
esig
n E
ntry
/ S
ynth
esis
Impl
emen
tatio
nTe
st (V
erifi
catio
n)O
pera
tions
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
8
How
the
Des
ign
Proc
ess F
or C
ompl
ex
Ele
ctro
nics
shou
ld fl
ow
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
9
Plan
ning
is w
here
we
shou
ld st
art
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
10
Requ
irem
ents
In a
typi
cal d
esig
n, th
e re
quire
men
ts fl
ow
dow
n fro
m th
e sy
stem
requ
irem
ents
. D
evel
opm
ent m
ay b
e by
the
wat
erfa
ll,
itera
tive,
spi
ral o
r oth
er d
evel
opm
ent
met
hodo
logy
. Mos
t pro
ject
s, s
oftw
are
and
CE
, use
an
itera
tive
appr
oach
as
they
flow
th
roug
h th
e de
sign
pro
cess
.
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
11
Requ
irem
ents
The
first
ste
p in
any
desi
gn p
roce
ss s
houl
d be
to d
efin
e an
d do
cum
ent t
he re
quire
men
ts a
nd c
onst
rain
ts u
nder
w
hich
the
CE
mus
t ope
rate
. Thi
s al
low
s yo
u to
thin
k th
roug
h th
e is
sues
and
doc
umen
t any
des
ign
deci
sion
s an
d tra
de-o
ffs.
Sof
twar
e ha
s a
wel
l def
ined
and
robu
st p
roce
ss. W
hile
th
is d
oes
not g
uara
ntee
suc
cess
, it a
llow
s yo
u to
find
an
d re
solv
e m
any
issu
es th
at m
ay a
rise.
C
ompl
ex E
lect
roni
cs d
esig
n is
ofte
n st
arte
d ba
sed
on th
e en
gine
ers
know
ledg
e of
the
syst
em, n
ot d
efin
ed
requ
irem
ents
.
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
12
An
Inte
grat
ed A
ssur
ance
App
roac
h
Req
uire
men
ts R
evie
ws
Com
plet
eV
erifi
able
Und
erst
anda
ble
Trac
eabl
eIn
terfa
ce C
ontro
l Doc
umen
t ver
ifica
tions
Fit p
lann
ed h
ardw
are
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
13
Trac
eabi
lity
Ana
lysis
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
14
Des
ign
Whe
ther
you
are
usi
ng U
nifo
rm M
odel
ing
Lang
uage
(UM
L), h
ardw
are
desc
riptio
n la
ngua
ge (H
DL)
or s
ome
othe
r for
m, t
his
is
whe
re y
ou d
efin
e th
e sy
stem
and
it’s
func
tion.
O
ne m
ajor
diff
eren
ce b
etw
een
CE
and
so
ftwar
e is
the
aspe
ct o
f tim
ing
and
conc
urre
ncy.
Th
e ba
sic
prem
ise
is th
e sa
me.
A g
ood
desi
gn is
exp
ecte
d.
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
15
Code
/ Im
plem
enta
tion
Alth
ough
HD
L is
not
true
cod
e, it
sha
res
man
y of
the
sam
e fe
atur
es a
nd a
ttrib
utes
of s
oftw
are.
The
di
ffere
nces
occ
ur d
urin
g th
e “c
ompi
le a
nd li
nk”
func
tions
. Dur
ing
synt
hesi
s (c
ompi
le),
the
desi
gn is
m
appe
d to
the
logi
c ga
tes
of th
e de
vice
.The
pl
acem
ent o
f the
logi
c bl
ocks
with
in th
e ch
ip, a
nd
the
rout
ing
betw
een
bloc
ks, a
re s
ome
of th
e pr
oces
ses
that
occ
ur d
urin
g im
plem
enta
tion.
Thi
s pr
oces
s is
loos
ely
com
para
ble
to th
e lin
king
ste
p in
so
ftwar
e.C
odin
g st
anda
rds,
cod
e re
view
s, a
nd b
est p
ract
ices
th
at a
re u
sed
by s
oftw
are
wor
k ve
ry w
ell o
n H
DL.
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
16
Eas
e of
cod
ing
Cod
ing
Sta
ndar
ds a
nd B
est P
ract
ices
wor
k w
ell o
n H
DLs
. The
y al
low
:R
eada
bilit
yS
tand
ard
Sig
nal n
ames
Nam
es d
o no
t cha
nge
acro
ss b
ound
arie
sC
omm
on re
gist
er n
ames
Mai
ntai
nabi
lity
Com
mon
nam
ing
conv
entio
nsC
ode
revi
ews
Etc
….
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
17
VH
DL
Code
Exa
mpl
e
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
18
Test Whi
le c
ompl
ex e
lect
roni
cs u
se te
st b
ench
es
and
timin
g m
odel
s, th
e id
ea o
f a w
ell d
efin
e su
ite o
f tes
t cas
es is
com
mon
in b
oth
disc
iplin
es. T
his
incl
udes
test
pla
ns, f
ault
inje
ctio
n an
d er
ror h
andl
ing
test
ing
and
verif
icat
ion.
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
19
Test
Met
hodo
logi
es
Bes
t Pra
ctic
esTe
st P
lans
Tr
acin
g to
requ
irem
ents
Feas
ible
Cov
er m
ore
than
just
suc
cess
…..
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
20
Rea
lity
Ch
eck
Man
y as
sura
nce
engi
neer
s, re
gard
less
of
thei
r spe
cial
ty, h
ave
little
und
erst
andi
ng o
f th
e co
mpl
exiti
es o
f the
se d
evic
es. A
ny re
view
do
ne w
ill on
ly b
e to
the
leve
l of k
now
ledg
e of
th
e as
sura
nce
engi
neer
. S
oftw
are
Ass
uran
ce E
ngin
eers
hav
e fa
ced
thes
e is
sues
and
use
man
y te
chni
ques
and
ch
eckl
ists
to in
sure
qua
lity.
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
21
Tech
niqu
es
Cha
nge
Impa
ct A
naly
sis
Dec
isio
n Ta
bles
/Tre
esD
esig
n E
valu
atio
nD
esig
n R
evie
wFa
ilure
Mod
e an
d E
ffect
Ana
lysi
sFa
ult T
ree
Ana
lysi
sFu
nctio
n an
d P
hysi
cal C
onfig
urat
ion
Aud
itsIn
terfa
ce A
naly
sis
Req
uire
men
ts E
valu
atio
nR
equi
rem
ents
Rev
iew
Ris
k A
naly
sis
Trac
eabi
lity
Ana
lysi
s
Rich
ard.
A.P
lasto
w @
nas
a.gov
Sr
. Sof
twar
e A
ssur
ance
Eng
inee
r (SA
IC)
22
Chec
klist
sP
lann
ing
Pha
seR
equi
rem
ents
Pha
seP
relim
inar
y D
esig
n P
hase
Det
aile
d D
esig
n P
hase
Impl
emen
tatio
n P
hase
Test
ing
Pha
seO
pera
tions
Pha
seA
ssur
ance
Pla
nnin
gA
ssur
ance
Pla
nnin
gM
odifi
catio
ns o
r Upg
rade
sM
odifi
catio
ns o
r Upg
rade
sA
udits
Aud
its(F
unct
iona
l Con
figur
atio
n, P
hysi
cal C
onfig
urat
ion
and
In-P
roce
ss)
Bes
t Pra
ctic
esB
est P
ract
ices
(Cod
e Re
view
)(C
ode
Revi
ew)
Test
ing
Test
ing
(Doc
umen
t Rev
iew
)(D
ocum
ent R
evie
w)
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