Motorola MPC823e Reference Manual page 458

Communication Processor Module
The MPC823e offers an extremely flexible set of communication capabilities. The remainder
of this section discusses all the possible ways you can configure the communication
processor module. Figure 16-2 illustrates a sample configuration for a personal digital
assistant (PDA) application that supports various communication links and protocols.
MPC823e
16.2 THE RISC MICROCONTROLLER
The 32-bit RISC microcontroller for the communication processor module resides on a
separate bus from the core and, therefore, does not impact the core's performance. The
microcontroller operates in conjunction with the serial channels and parallel port to
implement the user-programmable protocols and manage the serial DMA (SDMA) channels
that transfer data between the I/O channels and memory. The RISC microcontroller
architecture and instruction set are optimized for data communication and data processing
functions that are required by many wire-line and wireless communication standards. The
microcontroller also contains a multiply and accumulate (MAC) unit composed of a 16x16-bit
multiplier with two 40-bit accumulators that enable you to implement many DSP
applications.
Basically, the microcontroller handles low-level arithmetic tasks and DMA control activities,
which leaves the core free to handle the high-level activities. You could say it is the controller
of the communication processor module. It manages IDMA channel operation and contains
an internal timer that you can use to implement a maximum of 16 additional software timers.
16-4
USB
XCVR
SCC2
INFRA-RED
XCVR
SCC3
SMC1
SMC2
SPI BUS
SPI
2
I C BUS
2
I C
Figure 16-2. Example of a PDA Application
MPC823e REFERENCE MANUAL
USB
RS232
XCVR
USB
PORT
INFRA-RED
LINK
RADIO
INTERFACE
UART
PORT
SCREEN
DIGITIZER
VOICE
SYNTHESIZER
MOTOROLA