pef20550 Infineon Technologies Corporation, pef20550 Datasheet - Page 353

• Manufacturer Part Number: pef20550
• Description: Extended Line Card Interface Controller Elic
• Manufacturer: Infineon Technologies Corporation

CTAR
CBSR
CSCR
MUSAC
MOD
CFR
5.9.3.2 Space and Time Switch for 16 kBit/s Channels
The ELIC is optimized for the space and time switching of 64 kBit/s channels (8 bit
timeslots). The switching of 32 and 16 kBit/s subchannels is also supported, but these
channels can only be freely selected at the PCM interface. At the CFI, only one
subchannel per 8 bit timeslot can be switched (see chapter 5.4.2). Usually, this is
sufficient because on the IOM-2 interface, only one 16 kBit/s D channel per timeslot
needs to be switched. Up to four D channels may then be combined into a single 8 bit
PCM timeslot.
If a completely flexible space and time switch for contiguous 16 kBit/s channels is
required, the following method can be used:
The four CFI ports are connected in parallel as shown in figure 122. Each CFI port is
programmed via the CFI subchannel register (CSCR) to handle a different 2 bit sub-
timeslot position. With this configuration, any mixture of 16, 32 and 64 kBit/s channels
may be switched between the CFI and the PCM interfaces. Up to 128 16 kBit/s channels
per direction can be handled by the ELIC. The switching software must select the CFI
port number according to the required CFI subchannel position for each CFI - PCM
connection. The PCM subchannel position is selected via the control memory (CM) code
field (see table 40). For 32 and 64 kBit/s connections, only one CFI port of a given
timeslot may be programmed in order to avoid collisions on the CFI ‘bus’.
Semiconductor Group
= 0000 0010
= 0010 0000
= 0000 0000
= 0100 0100
= 1111 1111
B
B
B
B
B
= 02
= 20
= 00
= 03
= DE
H
H
H
H
H
PFS marks downstream CFI TS0
PFS marks downstream CFI bit 6, upstream
bits not shifted
64, 32, 16 kBit/s channels located on CFI bits
7 … 0, 7 … 4, 7 … 6
input mode 8
4.096 MHz device clock, conferencing
mode, A-law, even bits inverted
353
4M, output mode 4
Application Hints
PEB 20550
PEF 20550
4M
01.96