PEB 2091
PEF 2091
Functional Description
Within one FSC-period, 32 bit up to 256 bit are transmitted, corresponding to
DCL-frequencies ranging from 512 kHz up to 4096 kHz.
Three optimized IOM®-2 timing modes exist for:
Multiplexed Timing Mode1) (LT and NT-PBX)
Plain Timing Mode (NT, NT-Auto Activation, COT-512, NT-RP and LT-RP)
Terminal Timing Mode (TE and COT1536)
All applications utilize the same basic frame and clocking structure, but differ in the
number and usage of the individual channels.
Figure 24
Basic Channel Structure of IOM®-2
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
(activation/deactivation and other control function) by i.e., layer-2 controller.
• two bits MR and MX for the handshake procedure in the Monitor Channel
3.6.1.1 Multiplexed Timing Mode
Note 9: This section applies to the LT and the NT-PBX modes.
In multiplexed timing mode the IEC-Q supports bit rates from 256 kbit/s up to 2048 kbit/s
corresponding to DCL-frequencies from 512 kHz up to 4096 kHz.
The typical IOM®-2 line card or NT-PBX application comprises a DCL-frequency of 4096
kHz with a nominal bit rate of 2048 kbit/s. Therefore eight channels are available, each
consisting of the basic frame with a nominal data rate of 256 kbit/s. In LT mode the
downstream data (DD) are transferred on pin DIN, the upstream data (DU) on pin DOUT.
In NT-PBX mode the downstream data (DD) are transferred on pin DOUT, the upstream
1) This mode is also referred to as "Burst Mode"
Semiconductor Group
71
Data Sheet 01.99
INFINEON [ Infineon ]
