Motorola MPC823e User Manual

Communication Processor Module
MOTOROLA MPC823e REFERENCE MANUAL 16-157
BRGs
COMMUNICATION
16
PROCESSOR MODULE
16.8 THE BAUD RATE GENERATORS
The communication processor module contains four independent, yet identical, baud rate
generators (BRGs) that can be used with the universal serial bus, serial communication
controllers, and serial management controllers. The clocks produced in the baud rate
generator are sent to the bank-of-clocks selection logic, where they can be routed to the
universal serial bus, serial communication controllers, or serial management controllers. In
addition, the output of the baud rate generator can be routed to a pin to be used externally.
The following is a list of the baud rate generators’ main features:
• Four independent and identical baud rate generators
• On-the-fly changes are allowed
• Each baud rate generator can be routed to the universal serial bus, serial
communication controllers, or serial management controllers.
• A 16× divider option allows low baud rates at high system frequencies
• Each baud rate generator contains an autobaud support option
• Three of the baud rate generator outputs can be routed to the BRGOx pin
The baud rate generator block diagram is illustrated in Figure 16-63.
Figure 16-63. Baud Rate Generator Block Diagram
EXTC FIELD DIV 16
CD[0:11]
MUX
PRESCALER
DIVIDE BY
1 OR 16
12 BIT
COUNTER
CLOCK
BRGCLK
CLK2 PIN
AUTOBAUD
CONTROL
RX SOURCE
ATB BIT
BAUD RATE GENERATOR
BRGO
x
TO PIN
AND/OR
BANK OF
CLOCKS
TX SOURCE
CLK4 PIN
1–4,096

Motorola MPC823e Specifications

General

Brand	Motorola
Model	MPC823e
Category	Computer Hardware
Language	English