psf21911 ETC-unknow, psf21911 Datasheet - Page 31

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

NT or TE mode is selected via pins MS0-2 in stand-alone mode and via bits MS0-2 in
µP mode. Both the NT and TE mode utilize the same basic frame and clocking structure,
but differ in the number and usage of the individual channels.
Figure 12 Basic Channel Structure of IOM
Each frame consists of
• two 64 kbit/s channels B1 and B2
• the Monitor channel for transferring maintenance information
• two bits for the 16 kbit/s D-channel
• four command/indication (C/I) bits for controlling of layer-1 functions (U- and S-
• two bits MR and MX for the handshake procedure in the Monitor channel
2.3.1.1
In TE mode the IEC-Q TE provides a data clock DCL with a frequency of 1536 kHz. As
a consequence the IOM-2 interface provides three channels each with a nominal data
rate of 256 kbit/s.
• Channel 0 contains 144 kbit/s (for 2B+D) plus Monitor and Command/Indication
• Channel 1 contains two 64-kbit/s intercommunication channels plus Monitor and
• Channel 2 is used for IOM bus arbitration (access to the TIC bus). Only the Command/
The IOM-2 signals are:
DIN, DOUT
DCL
FSC
Semiconductor Group
transceiver).
channels for the layer-1 device.
Command/Indication channels for other IOM-2 devices.
Indication bits are used in channel 2.
TE Mode Frame Structure
768 kbit/s
1536 kHz output
8 kHz output
31
®
-2
IOM®-2 Interface
PSB 21911
PSF 21911
11.97