Nortel Circuit Card Installation Manual page 639

Card control functions
Control functions are provided by a microcontroller, a card LAN, and
signaling and control circuits on the E&M trunk card.
Microcontroller
The E&M trunk card contains a microcontroller that controls the internal
operation of the card. The microcontroller provides the following functions:
• card-identification
• self-test
• control of card operation
• maintenance diagnostics
Card LAN
The card LAN provides a serial communication link for transferring
maintenance data and control signals between the trunk card and the SSC
card. The card LAN controls the microcontroller. The following functions are
supported:
• providing card ID/RLS
• reporting self-test status
• polling from the controller card
• enabling/disabling of the DS-30X link
NT8D15 E&M Trunk card
Circuit Card Description and Installation
Page 639 of 906