Texas Instruments 990 User Manual page 75

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I 0. Number of RV ls (received). A count of the R Vis received. The host system interrupts the
local station's transmissions to send priority data. When the host system completes its data
transfer, the local station again BIDs for the line and resumes transmitting where it was
interrupted.
Local Host
Data
1111
RVI
Data
. .
ACKO
EOT
1111
BID
ACKO
. .
Data
ACKI
1111
Data/ETX
ACKO
4
EOT
BID
1111
ACKO
Data
11. Number of B/Ds overridden. A count of the BIDs that have been overridden. Both
stations have BID at the same time. The station designated as the primary station waits
one second and reBIDs. This BID overrides the secondary station's BID.
Local
•
BID
ACKO
Remote
BID
BID
12. Number of times the B/D.rhresho/d has been exceeded.• The line is BID for unsuccessfully
n times in a row. The value of n is the threshold.
13. Number of times the NAK threshold has been exceeded.• The station responds with NAK
n times in a row. The value of n is the threshold.
14. Number of times the ENQ threshold has been exceeded.• The station has responded with
ENQ n times in a row. The value of n is the threshold.
15. Number of rimes the IDLE threshold has been exceeded.• The station has not transmitted
anything for n seconds. The value of n is the threshold.
*These thresholds are set durin3 the building of the Emulator as. described in Appendix C.
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Digital Systems Group