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PEB 20321
PEF 20321
Host Memory Organization
Data Sheet
301
2001-02-14
Note: In the other modes these bit fields must be programmed to
‘
00
’
.
FA:
Flag Adjustment selected (in HDLC mode) or flag filtering (selected in
transparent mode A only if all fill/mask bits of the corresponding slots are
‘
1
’
).
In all other modes this bit must be set to
‘
0
’
. If flag adjustment is selected in
HDLC mode the number of interframe time-fill characters is FNUM minus one
eighth of the number of zero insertions in the frame proceeding the interframe
time-fill and belonging to the same transmit descriptor as FNUM.
If flag filtering is selected and fills a physical time slot in transparent mode A
the flag specified in TFLAG is recognized and extracted from the data stream.
In transmit direction the flag TFLAG is sent in all exception conditions, i.e.
abort, idle state etc.; if flag filtering is not selected,
‘
1
’
-bits are sent in this case.
Flag filtering is only allowed if all fill/mask codes are set to
‘
1
’
, i.e.
subchanneling is not allowed.
If flag filtering is not selected the bits in TFLAG have to be programmed to
‘
0
’
for TMA.
Defines the transmission mode:
00: Transparent mode A
01: Transparent mode B or transparent mode R.
10: V.110/X.30 mode
11: HDLC mode
Interframe Time-Fill; this bit determines the interframe time-fill for
HDLC mode:
IFTF =
‘
0
’
: 7E
H
characters are sent as interframe time-fill
IFTF =
‘
1
’
: FF
H
characters are sent as interframe time-fill.
First Rx Descriptor Address; points to the beginning of the Rx data chaining
list.
This descriptor is only interpreted with a fast receive abort or a receive jump
or a receive initialization command. It is read but ignored with any other
receive channel command.
First Tx Descriptor Address; points to the beginning of the Tx data chaining
list.
This descriptor is only interpreted with a fast transmit abort or a transmit jump
or a transmit initialization command. It is read but ignored with any other
transmit channel command.
MODE:
IFTF:
FRDA:
FTDA:
Table 31
TRV
00
01
10
11
No. of Repetitions
7
3
1
0
Transmission Rate
600 bit/s
1200 bit/s
2400 bit/s
4.8, 9.6, 19.2, 38.4 Kbit/s