PEB2085 SIEMENS [Siemens Semiconductor Group], PEB2085 Datasheet - Page 185

• Manufacturer Part Number: PEB2085
• Description: ISDN SubscribernAccess Controller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Mnemonic Register
XPR
XMR
XDU
RSC
TIN
Semiconductor Group
(addr. hex)
ISTA
EXIR (24)
EXIR (24)
ISTA
ISTA
(20)
(20)
(20)
Meaning
Transmit Pool Ready. Further
octets of an HDLC frame can be
written to XFIFO.
If XIFC was issued (auto mode),
indicates that the message was
successfully acknowledged with
S frame.
Transmit Message Repeat.
Frame must be repeated
because of a transmission error
(all HDLC message transfer
modes) or a received negative
acknowledgement (auto mode
only) from peer station.
Transmit Data Underrun. Frame
has been aborted because the
XFIFO holds no further data and
XME (XIFC or XTFC) was not
issued.
Receive Status Change.
A status change from peer
station has been received (RR
or RNR frame), auto mode only.
Timer Interrupt. External timer
expired or, in auto mode,
internal timer (T200) and repeat
counter (N200) both
expired.
Layer-2 Transmit
185
Reaction
Write data bytes in the XFIFO if
the frame currently being
transmitted is not finished or a
new frame is to be transmitted,
and issue an XIF, XIFC, XTF or
XTFC command. In auto mode
applications read the
information in chapter 2.5.5.2.
Transmission of the frame must
be repeated. No indication to
layer 3.
Transmission of the frame must
be repeated. Possible cause:
excessive software reaction
times.
Stop sending new I-frames.
Link re-establishment.
Indication to layer 3. (auto
mode)
Operational Description