4Links Diagnostic SpaceWire Interface DSI-RG408, Руководство пользователя

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Diagnostic SpaceWire Interface
EtherSpaceLink family User Manual
17. 6 . 3 5.
EtherSpaceLink_EI_flow_control()
S ynops i s
int EtherSpaceLink_EI_flow_control ( EtherSpaceLink DSI_unit,
int initial_fcts,
int flow_control
)
D esc ri pt i on
Th e EC SS -E- S T- 50 -12C S pac e W ir e s t a n da r d r e q u ir e s a t le as t one f lo w-c ont r ol to k en to be s ent to s t a r t
a
l
i
n
k , a
n
d
t
h
e m
a
x
i
mum
f
lo
w-c
ont
r
ol
c r
e
d i
t to be 5
6 N-Cha r s
(
as i
n
d i ca
te
d
b
y 7 f
lo
w-c
ont
r
ol to
k
en
s
).
F lo w-c ont r ol to k en s a r e no r m a ll y i ss ue d as spac e be c ome s a v a i l a ble i n t h e r e c e i ve bu ff e r . D a t a to k en s
(
ac
tu
a
ll
y N-Cha r s - da
t
a ,
en
d-
o
f-pack
et
a
n
d
e
rr
o
r -
en
d-
o
f-pack
et) m
ay
be
r
e
c
e
i
ve
d
u
p
to t
h
e numbe
r f
o
r
wh i ch c r e d i t has been i ss ue d .
Th
e
EtherSpaceLink_EI_flow_control()
o
f
t
h
e DS
I a
llo
ws
t
h
e l
i
n
k
to be
s
et out
s i d
e t
h
e
l i m i t s d e f i ne d b y t h e EC SS S pac e W ir e s t a n da r d .
A n i n i t i a l f lo w-c ont r ol i ss ue o f 0 to k en s sh oul d r e s ult i n a l i n k not s t a r t i n g . A n i n i t i a l f lo w-c ont r ol
i ss
ue o
f 8
o
r
mo
r
e
F CT s s h
oul
d ca
u
s
e
a
n e
rr
o
r
.
A utom a t i c iss u i n g o f f lo w-c ont r ol to k en s ca n be s u pp r e ss e d b y t h e DS I, le a v i n g t h e u s e r to ex p l i c i tl y
iss
ue
f
lo
w-c
ont
r
ol to
k
en
s
(
s
ee
EtherSpaceLink_write_EXTN
).
A
l
s
o
,
t
h
e t
r a
n
s
m
issi
on o
f d a
t
a ca
n
be a llo w e d b y t h e DS I d e s p i te t h e r e be i n g no a v a i l a ble c r e di t - i n o rd e r to te s t a r e c e i ve r’s be ha v i ou r .
Th
e
initial_fcts
pa r a
mete
r
o
f
EtherSpaceLink_EI_flow_control()
s
et
s
t
h
e numbe
r
o
f
f lo w-c ont r ol to k en s t ha t a r e s ent wh en t h e l i n k s t a r t s . Th is v a lue mu s t be bet w een 0 a n d 1 5; ot h e r w is e ,
a
n e
rr
o
r is r
e
p
o
r
te
d
.
Th e
flow_control
pa r a mete r o f
EtherSpaceLink_EI_flow_control()
m ay t ak e t h e v a lue
EtherSpaceLink_EI_normal_flow_control
,
o
r a c
omb
i
n
a
t
i
on (lo
gi ca
l
O R
) o
f
one o
r
bot
h
o
f
t h e ot h e r v a lue s:
EtherSpaceLink_EI_normal_flow_control
Op e r a te t h e S pac e W ir e l i n k u si n g t h e
s t a n d a rd S pac e W ir e f lo w-c ont r ol
a l g o ri t h m.
EtherSpaceLink_EI_transmit_anyway
A llo w d a t a to be s ent r e g a rd le ss o f t h e
a mount o f f lo w-c ont r ol c r e di t a v a i l a ble.
EtherSpaceLink_EI_no_automatic_FCT
Do not
a
utom
a
t i
ca
ll
y
s en d
a
n
y f
lo
w-
c
ont r ol to
k
en s
af
te r t
h
e l i n
k ha
s s t
a
r te d .
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