Nortel Networks Circuit Card 311 - Manual (Page 391)

Functional description 391
Functional description
Figure 102 "MSDL block diagram" (page 392) illustrates the MSDL functional
block diagram. The MSDL card is divided into four major functional blocks:
• CPU bus interface
• Micro Processing Unit (MPU)
• Memory
• Serial interface
Two processing units serve as the foundation for the MSDL operation:
the Central Processing Unit (CPU) and the MSDL Micro Processing Unit
(MPU). CS 1000 software, MSDL firmware, and peripheral software control
MSDL parameters. Peripheral software downloaded to the MSDL controls
MSDL operations.
The MSDL card’s firmware and software do the following:
• communicate with the CPU to report operation status
• receive downloaded peripheral software and configuration parameters
• coordinate data flow in conjunction with the CPU
• manage data link layer and network layer signaling that controls
operations connection and disconnection
• control operation initialization and addressing
• send control messages to the operations
CPU bus interface
The CPU bus transmits packetized information between the CPU and the
MSDL MPU. This interface has a 16-bit data bus, an 18-bit address bus,
and interrupt and read/write control lines.
Shared Random Access Memory (RAM) between the CPU and the MSDL
MPU provides an exchange medium. Both the CPU and the MSDL MPU
can access this memory.
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311 01.04 Standard
Release 5.0 23 May 2008
Copyright © 2003-2008, Nortel Networks
.