Motorola MPC823e - Page 455

MOTOROLA MPC823e REFERENCE MANUAL 16-1
COMMUNICATION
16
PROCESSOR MODULE
SECTION 16
COMMUNICATION PROCESSOR MODULE
The MPC823e communication processor module (CPM) provides a flexible and integrated
approach to communication-intensive environments. To reduce system frequency and save
power, the communication processor module has its own independent RISC microcontroller
that is optimized and tuned to handle serial communications. The communication processor
module offloads the core in the following ways:
• By reducing the interrupt rate. The core is interrupted only upon frame reception or
transmission, instead of on a per-character basis.
• By implementing some of the Layer-2 multiply-and-accumulate processing, which
provides more CPU bandwidth for higher layer processing.
• By supporting multibuffer memory data structures that are convenient for software
handling.
16.1 FEATURES
The following is a list of the communication processor module’s main features. For quick
reference purposes, the superscripted number following each item below is the page
number where the feature is described.
• 32-Bit RISC Microcontroller
4
• Flexibility of Four General-Purpose 16-Bit Timers or Two 32-Bit Timers
74
• A Serial Interface with a Time-Slot Assigner
112
• Four Independent Baud Rate Generators
157
• Two Full-Duplex Serial Communication Controllers (SCC2 and SCC3)
163
• A Universal Serial Bus Controller
350
• Two Full-Duplex Serial Management Controllers (SMCs)
382
• Serial Peripheral Interface (SPI) Support for Master or Slave
433
•I
2
C Bus Controller Support for Master or Slave
456
• General-Purpose Parallel Interface Ports with Open-Drain Capability
477
• Communication Processor Module Interrupt Controller with Flexible Priorities
499