4Links Diagnostic SpaceWire Interface DSI-RG408, Руководство пользователя

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Diagnostic SpaceWire Interface
EtherSpaceLink family User Manual
p r o gr a m , be f o r e t h e S pac e W ir e l i n ks a r e en a ble d u s i n g
EtherSpaceLink_set_mode()
. Th i s
w i
ll be
r
el
i a
ble.
If
EtherSpaceLink_write_buffer_empty()
,
EtherSpaceLink_link_connected()
o r
EtherSpaceLink_get_control_packet()
a r
e
ca
lle
d
to
d
ete
r
m
i
ne t
h
e
s
t
a
tu
s
o
f a
S pac e W ir e l i n k a t t h e sa me t i me as a n y o f t h e l i n ks a tt ach e d to t h e E t h e r S pac eL i n k un i t i s
r
etu
r
n
i
n
g
S
pac
e
W ir
e t
r aff i c , s
ome o
f
t
ha
t S
pac
e
W ir
e
da
t
a
m
ig h
t be lo
s
t. Su
ch da
t
a
lo
ss i s i
n
d i ca
te
d
b y t h e fa i l i n g r e s ult c o d e t ha t i s r etu r ne d .
A
bette
r way
to
d
ete
r
m
i
ne t
h
e
s
t
a
tu
s
o
f a
l
i
n
k i s
to
i ss
ue t
h
e
r
e
q
ue
s
t embe
dd
e
d i
n t
h
e
r
out
i
ne
s
l i s te d a bove u s i n g
EtherSpaceLink_write_packet(EtherSpaceLink_SPECIAL)
, to
wa i
t
f
o
r
t
h
e
asy
n
ch r
onou
s s
t
a
tu
s i
n
d i ca
t
i
on u
s i
n
g
EtherSpaceLink_read_packet_full()
, a n d to p r o c e ss t h e r e sp on s e wh en i t a rri ve s .
17.5.4. Us i n g M ult i ple Th r e ad s Sa fely
I
t
i s p
o
ss i
ble to
r
un t
h r
e
ads i
n t
h
e
A
P
I app
l
i ca
t
i
on on t
h
e
h
o
s
t
c
om
p
ute
r, a
n
d
t
h i s ca
n
s i
m
p
l
i fy i
t
s
s
t r u
c
tu r e
- a
t
a c
o
s
t o
f
m
a
n
a
gi n g t
h
e
c
on
c
u rr en
cy p
r o
p
e r l
y
.
Typ
i
ca
ll
y
i n
E
t
h
e r S
pac
eL i n
k p
r o gr
a
m
s
,
t
w
o t
h r
e
ads a r
e u
s
e
d:
one t h r e ad g ene r a te s t r aff i c a n d s en ds i t on S pac e W ir e to t h e c onne c te d i n s t r ument v i a t h e
E
t
h
e
r
S
pac
eL
i
n
k
un
i
t;
t h e s e c on d t h r e ad r e ads a ll o f t h e t r aff i c t ha t i s r etu r ne d f r om t h e E t h e r S pac eL i n k un i t to t h e h o s t
c
om
p
ute
r, d
e
- i
nte
r
le
a
ve
s i
t
, r
e
c
o
r ds i
t
, a
n
d p
o
ss i
bl
y
u
s
e
s
t
h
e
i
n
f
o
r
m
a
t
i
on
r
e
c
e
i
ve
d
to
g
ene
r a
te
f u r t h e r out g o i n g S pac e W ir e t r aff i c .
Th
e
r
em
a i
n
i
n
g i ss
ue
i s h
o
w
to
saf
el
y pass i
n
f
o
r
m
a
t
i
on
f r
om t
h
e
r
e
c
e
i
ve t
h r
e
ad
b
ack
to t
h
e t
r a
n
s
m
i
t
t h r e ad . Th i s mu s t be d one u s i n g s em aph o r e s o r ot h e r f o r m s o f mutu a l ex c lu s i on to en s u r e t ha t r ac e
c
on
d i
t
i
on
s a
n
d c
on
c
u
rr
ent
w ri
te
s
to v
a ri a
ble
s a r
e not
p
o
ss i
ble.
T r a
n
sf
e
rri
n
g s i
m
p
le
s
t
a
tu
s i
n
f
o
r
m
a
t
i
on
f r om t h e r e c e i v i n g t h r e ad b ack to t h e t r a n s m i tt i n g t h r e ad i s u s u a ll y s t r a ig h t f o r wa r d .
SpW.c
a
n
d
t
h
e ex
a
m
p
le
i
n
s
e
c
t
i
on
1 7
.5.
6,
“
A
n
Ad
v
a
n
c
e
d A
P
I E
x
a
m
p
le”
, c
ont
a i
n
s
ex
a
m
p
le
c
o
d
e to
i llu s t r a te t h e u s e o f mult i p le t h r e ads .
17.5.5.
Maxi
m
i
s
i
n
g
the Th
r
ou
g
hput of
A
P
I
P
r
o
gra
ms
DS
I
un
i
t
s s
u
pp
o
r
t u
p
to e
ig h
t S
pac
e
W ir
e
p
o
r
t
s a
n
d i
t
i s p
o
ss i
ble to
d ri
ve
a
ll o
f
t
h
e
s
e
c
on
c
u
rr
entl
y
.
I
n
o r d e r to m a x i m i s e t h e t h r ou g hp ut o f mult i p le S pac e W ir e l i n ks , s eve r a l c on c e p t s mu s t be c on s i d e r e d:
Se
pa r a
te
r
e
c
e
i
ve
a
n
d
t
r a
n
s
m
i
t t
h r
e
ads sh
oul
d
be u
s
e
d i
n t
h
e
app
l
i ca
t
i
on
p r
o
gr a
m
,
to
r
e
d
u
c
e
a
n
y
ove r h e ad o f p oll i n g ;
Th
e
app
l
i ca
t
i
on
p r
o
gr a
m
sh
oul
d
not
c
o
py da
t
a f r
om one bu
ff
e
r
to
a
not
h
e
r
unne
c
e
ssa ri
l
y
.
Bu
sy-wa i
t
i
n
g
mu
s
t be
a
vo
i d
e
d , p
o
ss i
bl
y
b
y
ex
p
l
i c i
tl
y
m
a
n
a gi
n
g
t
h
e
sch
e
d
ul
i
n
g
o
f
t
h
e t
h r
e
ads
;
Th e app l i ca t i on p r o gr a m g ene r a te s S pac e W ir e pack et s f o r t r a n s m i ss i on , a n d t h e A P I f o r wa r ds
t
h
e
s
e
a
lon
g
t
h
e
TC
P/
I
P
c
onne
c
t
i
on to t
h
e DS
I i
n t
h
e o
r d
e
r
t
ha
t t
h
e
y a r
e
g
ene
r a
te
d
.
Wh
en t
h
e
y a r
e
r e c e i ve d a t t h e DS I , t h e y a r e t r a n s m i tte d to t h e app r o p ri a te S pac e W ir e p o r t. I t i s ne c e ssa r y to
p r
event
a
n
y
o
f
t
h
e S
pac
e
W ir
e t
r a
n
s
m
i
t bu
ff
e
r s i
n t
h
e DS
I f r
om be
c
om
i
n
g f
ull
a
n
d
blo
ck i
n
g
t
h
e
TC P/ I P c onne c t i on. Th i s i s be s t d one w i t h i n a n app l i ca t i on p r o gr a m b y s en d i n g s m a ll [ m ay be
6
0
-
500 b
y
te
]
EtherSpaceLink_PART_EOP_EEP
-
te
r
m
i
n
a
te
d pack
et
s f
ollo
w
e
d
b
y a
n
4Links Limited
www.4Links.co.uk
support@4Links.co.uk
page 55 of 130
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