Nortel Networks 553-3001-211 manual NTBK51 Downloadable D-channel Handler daughterboard Page 775

NTBK51 Downloadable D-channel Handler daughterboard Page 775 of 894

Functional description

The main functional blocks of the NTBK51 architecture include the following:

•Microprocessors

•Main memory

•Shared memory

•EPROM memory

•Flash EPROM memory

•EEPROM memory

•Serial communication controller

•Sanity timer

•Bus timer

Microprocessors

One microprocessor handles data transfer between each serial interface and software, reports the status of each port and takes commands from the software to control the activities of the ports. A high performance MPU supports the D-channel from the PRI card and other software applications running simultaneously on other ports of the DDCH card.

The microprocessor performs the following functions:

•sanity check and self tests

•message handling between the CS 1000S, CS 1000M Cabinet, and Meridian 1 PBX 11C Cabinet and the card

•four port serial communication controller handling with Direct Memory Access (DMA)

•program download from the Small System Controller

Circuit Card Description and Installation