4Links Diagnostic SpaceWire Interface DSI-RG408, User Manual, Page: 39 / 130

Diagnostic SpaceWire Interface
EtherSpaceLink family User Manual
1 3 . Opt i on CO - Cont r olle d Outputs
Usi n g t h e CO o p t i on , i t is p o ssi ble to s y n ch r on is e t h e t r a n s m issi on o f a n y cha r ac te r i n t h e t r a n s m i t
s
t
r
e
a
m to
a
n exte
r
n
a
l
c
lo
ck
t
r a
n
si
t
i
on.
Lo w- to -h ig h t r a n si t i on s on t h e r e a r - mounte d S MA c onne c to r pa ir J 1 - J 2 p e r m i t t h e t r a n s m issi on o f
t
r aff i c
be
y
on
d
e
ach
H
O
LD
cha r ac
te
r
t
ha
t
is i
n
s
e
r
te
d i
nto t
h
e t
r a
n
s
m
issi
on
s
t
r
e
a
m.
Th
e
h ig h
lo
gi c
t h r e s h ol d is app r ox i m a tel y 1 V . See s e c t i on 3 . 3, “S MA S y n ch r on i za t i on C onne c to rs ” , f o r d et a i l s o f t h e
DS
I’s
S
MA s y
n
ch r
on
i za
t
i
on
c
onne
c
to
rs
.
Each p
o
r
t on t
h
e DS
I ha s a
t
r a
n
s
m
i
t bu
ff
e
r
o
f app r
ox
i
m
a
tel
y 32 k
b
y
te
s, wh i ch s
to
r
e
s d a
t
a cha r ac
te
rs,
EO
P to
k
en s
a
n d H
O
LD m
a
r
k
e rs . I t is not
p
o ssi ble to
q
ue r
y
t
h
e numbe r o
f pack
et s i n t
h
is bu
ff
e r .
C
ont
r
ol
is a
t t
h
e S
pac
e
W ir
e to
k
en level
-
t
h
e u
s
e
r ch
oo
s
e
s
ex
ac
tl
y wh
e
r
e to
d
el
ay
t
h
e
d a
t
a s
t
r
e
a
m unt
i
l
t h e next S MA sig n a l t r a n si t i on o cc u rs, b y i n s e r t i n g a H O LD m a r k e r a t t ha t p o i nt. H O LD m a r k e rs m ay
be
i
n
s
e
r
te
d i
n t
h
e
d a
t
a s
t
r
e
a
m
s f
o
r
mult
i p
le S
pac
e
W ir
e
p
o
r
t
s
; t
h
e u
s
e
r is r
e
s p
on
si
ble
f
o
r
bu
ff
e
ri
n
g
s u ff i c i ent S pac e W ir e t r aff i c a t e ach p o r t.
I
n t
h
e ex
a
m
p
le
s
belo
w ,
t
h
e DS
I wa s s y
n
ch r
on
is
e
d
v
i a a
n
AT I
to
a
n
IRIG s
ou
r c
e
, a
n
d
t
h
e t
rigg
e
r sig
n
a
l
wa s g ene r a te d a t one p ul s e p e r s e c on d f r om t h e IRIG s ou r c e. Th e DS I ha d a loo p b ack c onne c to r on
p
o
r
t
4 , a
n
d
t
h
e
p
o
r
t
4
t
r a
n
s
m
i
t
s p
ee
d wa s 1
00
M
b/
s
.
Th
e
c
ont
r
oll
i
n
g s
o
f
t
wa r
e
wa s
SpWIO
.
I
n t
h is f irs
t ex
a
m
p
le
,
t
h
e
r
e
is a s y
n
ch r
on
is a
t
i
on to t
h
e exte
r
n
a
l
c
lo
ck a
t t
h
e
s
t
a r
t o
f
e
ach pack
et
:
@4 (/w s) 5*{ hold 0 0 0 0 eop }
Tx:@4 /* /w s */ HOLD #00 #00 #00 #00 EOP
Tx:@4 HOLD #00 #00 #00 #00 EOP
Tx:@4 HOLD #00 #00 #00 #00 EOP
Tx:@4 HOLD #00 #00 #00 #00 EOP
Tx:@4 HOLD #00 #00 #00 #00 EOP
Rx:@4 /*208:22:48:09.000 000 538 9s [-6]*/ #00 #00 #00 #00 EOP
Rx:@4 /*208:22:48:10.000 000 566 9s [-6]*/ #00 #00 #00 #00 EOP
Rx:@4 /*208:22:48:11.000 000 558 9s [-6]*/ #00 #00 #00 #00 EOP
Rx:@4 /*208:22:48:12.000 000 497 6s [-6]*/ #00 #00 #00 #00 EOP
Rx:@4 /*208:22:48:13.000 000 569 6s [-6]*/ #00 #00 #00 #00 EOP
F
ollo
w i
n
g
t
h
e
risi
n
g
e
dg
e o
f
t
h
e
c
lo
ck
on t
h
e S
MA i
n
p
ut
c
onne
c
to
r,
t
h
e
r
e
is a d
el
ay
be
f
o
r
e t
r a
n
s
m
issi
on
onto S pac e W ir e o f t h e b y te f ollo w i n g t h e H O LD cha r ac te r ; a t 1 00 M b/ s, t h is is app r ox i m a tel y 500 n s .
I n t h is s e c on d ex a m p le , t h e r e is a s y n ch r on is a t i on on e ach b y te o f a pack et ( a n d i t s EO P) :
@4 (/w sme) hold 0 hold 0 hold 0 hold 0 hold eop
Tx:@4 /* /w sme */ HOLD #00 HOLD #00 HOLD #00 HOLD #00 HOLD EOP
Rx:@4 /*208:22:47:44.000 000 522 9s [-6]*/ #00
Rx:@4 /*208:22:47:45.000 000 573 6s [-6]*/ #00
Rx:@4 /*208:22:47:46.000 000 549 6s [-6]*/ #00
Rx:@4 /*208:22:47:47.000 000 597 6s [-6]*/ #00
Rx:@4 /*208:22:47:48.000 000 497 6s [-6]*/ EOP
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