HP 30240A Installation And Service Manual page 36

Host to LANIC Communication
The host communicates with LANIC through channel registers and data
structures stored in system memory. Basic channel communication registers
provide for channel identification, interrupt control, and diagnostics. Of primary
importance are the Control Register (CR) and Status Register (SR), which provide
for the input and output of control and status information. Link-level
commands and status are passed via two queue structures stored in system
memory shared by the LANIC and the host.
UI
ABLE
L
-.-J
1--------1
1 1
r - - - - - ,
1
1
--L
~:
1
I
PROTOCOL AUI
CONTROLLER
-
INTERF'ACE
I
C
I
I
I
I~
DNA
I~
I
INTERF'ACE
T
I
LL
Z-80B
I
I~
~
I
MPU
H-
I~
I
I
I~
~
I
I
CHANNEL
I~
LOGIC
I
16 KSYTE
,-
AND
1
1
RAM
REGISTERS
,
I
115
I
I
Ii
I
I
BACKPLANE
I
W-
e
KSYTE
I
INTERF'ACE
I
ROM
MAIN
MODULE
I
MODULE
Figure 3-1. LANIC Functional Block Diagram
Principlt~S
of Operation
3-2