Micro Controller Unit (Mcu); Ipe Interface Logic - Meridian Nortel 1 Option 11C Technical Reference Manual

Micro Controller Unit (MCU)

The MCU coordinates and controls the operation of the SILC. It has internal
memory, a reset and sanity timer, and a serial control interface.
The memory consists of 32 K of EPROM which contains the SILC operating
program and 8 K of RAM used to store interface selection and other functions
connected with call activities.
The reset and sanity timer logic resets the MCU.
The serial control interface is an IPE bus used by the MPU to communicate
with the S/T transceivers.

IPE interface logic

The IPE interface logic consists of a Card-LAN interface, an IPE bus
interface, a maintenance signaling channel interface, a digital pad, and a clock
controller and converter.
The Card-LAN interface is used for routine card maintenance, which includes
polling the line cards to find in which card slot the SILC is installed. It also
queries the status and identification of the card, and reports the configuration
data and firmware version of the card.
The IPE bus interface connects one IPE bus loop that has 32 channels
operating at 64 kbps and one additional validation and signaling bit.
The maintenance signaling channel (MSC) interface is used to communicate
signaling and card identification information from the Meridian 1 CPU to the
SILC MCU. The signaling information also contains maintenance
instructions.
The digital pad provides gain or attenuation values to condition the level of
the digitized transmission signal according to the network loss plan. This sets
transmission levels for the B-channel circuit-switched voice calls.
The clock recovery circuit recovers the clock from the local exchange.
The clock converter converts the 5.12 MHz clock from the IPE backplane into
a 2.56 MHz clock to time the IPE bus channels and an 8 kHz clock to provide
PCM framing bits.
NT6D70 SILC line card
Option 11C and 11C Mini
Page 417 of 544
Technical Reference Guide