PEB2085 SIEMENS [Siemens Semiconductor Group], PEB2085 Datasheet - Page 209

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

4.1.9
Value after reset: 00
XMR
XDU
Note:
PCE
RFO
SOV
MOS
Semiconductor Group
7
Transmit Message Repeat
The transmission of the last frame has to be repeated because:
– the ISAC-S has received a negative acknowledgement to an I-frame in auto-mode
– or a collision on the S-bus has been detected after the 32
Transmit Data Underrun
The current transmission of a frame is aborted by transmitting seven "1's" because
the XFIFO holds no further data. This interrupt occurs whenever the processor has
failed to respond to an XPR interrupt (ISTA register) quickly enough, after having
initiated a transmission and the message to be transmitted is not yet complete.
When an XMR or and XDU interrupt is generated, it is not possible to send
transparent frames or I-frames until the interrupt has been acknowledged by reading
EXIR.
Protocol Error
Used in auto-mode only.
A protocol error has been detected in auto-mode due to a received
– S- or I-frame with an incorrect sequence number N(R) or
– S-frame containing an I-field.
– I-frame which is not a command.
– S-frame with an undefined control field.
Receive Frame Overflow
The received data of a frame could not be stored, because the RFIFO is occupied.
The whole message is lost.
This interrupt can be used for statistical purposes and indicates that the processor
does not respond quickly enough to an RPF or RME interrupt (ISTA).
Synchronous Transfer Overflow
The synchronous transfer programmed in STCR has not been acknowledged in time
via the SC0/SC1 bit.
MONITOR Status
A change in the MONITOR Status Register (MOSR) has occured (IOM-2).
A new MONITOR channel byte is stored in MOR (IOM-1).
Extended Interrupt Register
XMR
(according to HDLC/LAPD)
frame.
XDU
H
PCE
RFO
209
SOV
EXIR
MOS
Read
SAW
Register Description
nd
data byte of a transmit
WOV
Address 24
0
H