PEB2085 SIEMENS [Siemens Semiconductor Group], PEB2085 Datasheet - Page 216

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

Note 1: S frames are handled automatically and are not transferred to the microprocessor.
Note 2: For U frames (bit 0 of RHCR = 1) the control field is as in the modulo 8 case.
Note 3: For I frames (bit 0 of RHCR = 0) the compressed control field has the same format
Note 4: I-field.
4.1.19
EA
In all message transfer modes except in transparent modes 2 and 3, TEI2 is used by the ISAC-
S for address recognition. In the case of a two-byte address field, it contains the value of the
second programmable Terminal Endpoint Identifier according of the ISDN LAPD protocol.
In auto and non-auto-modes with one-byte address field, TEI2 is a response address,
according to X.25 LAPB.
4.1.20
Value after reset: 0XX00000
XAC
Semiconductor Group
as in the modulo 8 case, but only the three LSB’s of the receive and transmit counters
are visible:
Address Field Extension Bit
This bit is to be set to "1" according to HDLC/LAPD.
Transmitter Active
The HDLC transmitter is active when XAC = 1. This bit may be polled. The XAC bit is
active when
– either an XTF/XIF command is issued and the frame has not been completely
– or the transmission of an S frame is internally initiated and not yet completed.
7
TEI2 Register
Receive Frame Byte Count High
7
7
XAC
transmitted
N(R)2-0
VN1
2
VN0
.
TEI2
OV
P
216
RBC11
RBCH
TEI2
RBC10
N(S)2-0
Read
Write
RBC9
Register Description
RBC8
EA
0
Address 29
Address 2A
0
0
0
H
H