Intel MCS48 User Manual page 396

8291
( START
J
C
•""
)
SET
DAV
HIGH
PUT
OR CHANGE
DATA ON
DATA
LINES
ERROR
CONDITION
(
"
)
NRFD
SIGNAL
LINES
GOES
HIGH
YES
ONLY WHEN
ALL ACCEPTORS ARE READY
SET
DAV LOW
DATA
IS
VALID
AND MAY
NOW
BE ACCEPTED
NDAC
SIGNAL
LINE
STAYS LOW UNTIL
SET
DAV
HIGH
ALL ACCEPTORS HAVE ACCEPTED
IT
DATA
IS
NOT TO
BE
CONSIDERED
VALID AFTER
THIS TIME
J
SET
NRFD AND
NDAC LOW
NO
S
READY
TO ACCEPT
DATA?
SET
NRFD
HIGH
ACCEPT
DATA
BYTE
SET
NRFD LOW
SET
NDAC
HIGH
FLOW DIAGRAM
OUTLINES SEQUENCE OF EVENTS DURING TRANSFER OF
DATA
BYTE.
MORE THAN ONE
LISTENER
AT A
TIME CAN ACCEPT DATA
BECAUSE OF LOGICAL AND CONNECTION OF NRFD AND NDAC
LINES.
Figure
C.2.
Handshake
Flowchart.
8-106
00229A