Nortel NT1R20 Description page 107

Microcontrollers
The line-side T1 card contains two microcontrollers that control the internal
operation of the card and the serial card LAN link to the controller card. The
microcontrollers control the following:
— reporting to the CE CPU via the card LAN link:
• card identification (card type, vintage, serial number)
• firmware version
• self-test results
• programmed unit parameter status
— receipt and implementation of card configuration:
• control of the T1 line interfaces
• enabling/disabling of individual units or entire card
• programming of loop interface control circuits for
administration of channel operation
• maintenance diagnostics
— interface with the line card circuit:
• converts on/off-hook, and ringer control messages from the DS-30X
loop into A/B bit manipulations for each time slot in the T1 data
stream, using robbed bit signaling.
— the front panel LED when the card is enabled or disabled by instructions
from the NT8D01 controller card.
Card LAN interface
Maintenance data is exchanged with the Common Equipment CPU over a
dedicated asynchronous serial network called the Card LAN link. The Card
LAN link is described in "Card LAN link" on page 21.
NT5D11 Line-side T1 Interface Card Page 83 of 290
Line cards Description