PEF2091 Siemens Semiconductor Group, PEF2091 Datasheet - Page 88

• Manufacturer Part Number: PEF2091
• Description: ICs for Communications(ISDN Echocancellation Circuit)
• Manufacturer: Siemens Semiconductor Group

Semiconductor Group
3.7.4.1
XIN/XOUT
A free running crystal or other clock source shall provide a 15.36-MHz base clock (see
also "External Circuitry", page 249 for more informations about crystal properties).
CLS
In this mode version 5.3 provides an unsychronized 15.36 MHz clock on CLS. This clock
can be used by the PLL as a base clock. It is also available in power down.
3.7.4.2
XIN/XOUT
Pin XOUT should be left open.
The synchronized 15.36 MHz clock should be provided on pin XIN.
The dynamic characteristics of this clock are described in "LT Modes", page 281.
Clock CLS
In this mode a 512 kHz clock is provided on CLS. This clock signal is not synchronous
to the received U-interface signal. It is also available in power down.
3.7.5
Figure 36
Because pair gain systems do not need to synchronize onto a PTT-master clock, a free
running 15.36-MHz system clock may be used at the exchange side. In COT mode the
CLS=7680 kHz
DCL=512 kHz
FSC=8 kHz
NT Repeater
LT Repeater
COT-512 and COT-1536 Mode
Clocks in COT-512 Mode
COT-512
XIN
XOUT
Interface
U
88
Figure 36
CLS=7680 kHz
DCL=1536 kHz
FSC=8 kHz
Clocks in COT-1536 Mode
Functional Description
COT-1536
XIN
XOUT
Data Sheet 01.99
PEB 2091
PEF 2091
Interface
U