COM20051 Datasheet, PDF (31/82 Pages) List of Unclassifed Manufacturers – Integrated Microcontroller and ARCNET (ANSI 878.1) Interface

BIT
BIT NAME
7
My
Reconfiguration
6
Duplicate ID
5
Receive
Activity
4
Token Seen
3
Excessive NAK
2
Tentative ID
1
New Next ID
1,0 (Reserved)
Table 8 - Diagnostic Status Register
SYMBOL
DESCRIPTION
MY-
RECON
DUPID
RCVACT
This bit, if high, indicates that a past reconfiguration was
caused by this node. It is set when the Lost Token Timer
times out, and is typically read following an interrupt caused by
RECON. Refer to the Improved Diagnostics section for further
detail.
This bit, if high, indicates that the value in the Node ID
Register matches both Destination ID characters of the token
and a response to this token has occurred. The EOT
character and the trailing zero's are also verified. A logic "1"
on this bit indicates a duplicate Node ID, thus the user should
write a new value into the Node ID Register. This bit is only
useful for duplicate ID detection when the device is off
line, that is, when the transmitter is off. When the device is
on line it will be set every time the device gets the token. This
bit is reset automatically upon reading the Diagnostic Status
Register. Refer to the Improved Diagnostics section for further
detail.
This bit, if high, indicates that data activity (logic "1") was
detected on the RXIN pin of the device. Refer to the Improved
Diagnostics section for further detail.
TOKEN
This bit, if high, indicates that a token has been seen on the
network, sent by a node other than this one. Refer to the
Improved Diagnostic section for further detail.
EXCNAK
This bit, if high, indicates that either 128 or 4 Negative
Acknowledgements have occurred in response to the Free
Buffer Enquiry. This bit is cleared upon the "POR Clear Flags"
command. Reading the Diagnostic Status Register does not
clear this bit. This bit, when set, will cause an interrupt if the
corresponding bit in the IMR is also set. Refer to the Improved
Diagnostics section for further detail.
TENTID
NEW
NXTID
This bit, if high, indicates that a response to a token whose
DID matches the value in the Tentative ID Register has
occurred. In addition, the EOT character is checked. The
second DID and the trailing zero's are not checked. Since
each node sees every token passed around the network, this
feature can be used with the device on-line in order to build
and update a network map. Refer to the Improved
Diagnostics section for further detail.
This bit, if high, indicates that the Next ID Register has been
updated and that a node has either joined or left the network.
Reading the Diagnostic Status Register does not clear this bit.
This bit, when set, will cause an interrupt if the corresponding
bit in the IMR is also set. The bit is cleared by reading the
Next ID Register.
These bits are undefined.
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