psf21911 ETC-unknow, psf21911 Datasheet - Page 89

• Manufacturer Part Number: psf21911
• Description: Isdn Echocancellation Circuit Terminal Applications Iec-q
• Manufacturer: ETC-unknow

2.7
Important: This chapter applies only in µP mode and if DCL = 1.536 MHz (TE mode).
If DCL = 1.536 MHz the IOM-2 interface consists of three IOM-2 channels. The last octet
of an IOM-2 frame includes the S/G and the BAC bit (chapter 2.3.1.1, page 31). Either
or both bits can be used in various applications including
• the D-channel arbitration in a PBX via an ELIC on the linecard
• the synchronization of a base station in radio in the local loop (RLL) or wireless PBX
The S/G is always written and never read by the IEC-Q TE. Its value depends on the last
received EOC-command and on the status of the BAC bit.The processing mode for the
S/G bit is selected via bits SWST:BS, SWST:SGL and ADF:CBAC according to table 18.
A detailed description of the S/G bit in all modes is provided in Appendix B.
Table 18
SWST:
BS
Semiconductor Group
applications
0
0
0
1
1
1
SGL
S/G Bit and BAC Bit in TE Mode
S/G Processing Mode
0
1
0
1
1
1
ADF:
CBAC
0
1
0
1
x
x
Description (X is don’t care)
S/G bit always "0"
S/G bit always "1"
S/G bit set to "1" continously with EOC
25
received
BAC bit controlls S/G-bit, upstream D-
channel not affected
S/G bit set to "1" for 4 IOM-frames with
EOC 25
to "0" after that
S/G bit set to "1" continously with EOC
25
received
S/G bit set to "1" continously with EOC
25
received
BAC bit controlls S/G bit and upstream D-
channel according to table 19.
H
H
H
receivced, reset to "0" with EOC 27
receivced, reset to "0" with EOC 27
received, reset to "0" with EOC 27
H
receivced, automatically reset
89
S/G Bit and BAC Bit in TE Mode
H
H
H
Application
S/G and BAC are
handled by other
devices than the
IEC-Q TE
ELIC on linecard,
Interframe fill of
terminals
contains zeroes
(e.g. ’01111110’)
Synchronizaiton
of base station,
e.g. IBMC or
MBMC
ELIC on linecard,
Interframe fill of
terminals are
’ones’
(default)
PSB 21911
PSF 21911
11.97