CD1865 Datasheet, PDF (67/150 Pages) Intel Corporation – Intelligent Eight-Channel Communications Controller

Intelligent Eight-Channel Communications Controller — CD1865
Figure 23. No New Data Timer Logic
BACKGROUND SCANNING
DETECTS NEW CHARACTER
ARRIVED
...FROM OTHER
BACKGROUND
PROCESSING...
PUT CHARACTER IN FIFO;
RELOAD TIMER
RESUME BACKGROUND
SCANNING LOOP...
TIMER
=0
N
?
Y
IS
FIFO
EMPTY
?
Y
NO NEW DATA
TIMEOUT FEATURE
ENABLED
?
Y
NNDT
INTERNAL FLAG
’ARMED’
?
Y
CLEAR NNDT
INTERNAL FLAG
N
POST RECEIVE GOOD
DATA SERVICE REQUEST
N
N
POST RECEIVE EXCEPTION
SERVICE REQUEST
RESUME BACKGROUND
SCANNING LOOP...
Datasheet
67