Texas Instruments 990 User Manual page 21

2280117
DX10
PRIMARY
USER TASK(S)
.
,
A~
"
LEVEL 4
(END-TO-END
CONTROL)
H
4t.
.'
.,
.... LOGICAL INTERFACES BETWEEN TASKS_
~
..
LEVEL 3 _ PACKET LEVEL LOGICAL INTERFACES _
(FLOW CONTROL)
~
..
LEVEL 2
L..
LINE CONTAOL LOGICAL INTERFACE ..
(HOLe LINE .. ..
CONTROL)
LEVEL 1
(FCCC PORT)
~
LINE LEVEL PHYSICAL INTERFACE
..
....
..
Introduction
TX5
SECONDARY
USER TASK(S)
,.
LEVEL 4
(ENO-To-ENO
CONTROL)
.~
H
.,
.'
..
'
LEVEL 3
(FLOW CONTROL)
LEVEL 2
(HOLC LINE
CONTROL)
LEVEL 1
(LLM PORT)
Figure 1-3
Level Diagram of HDLC Canmunications System
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