MOTOROLA
Contents
xxi
CONTENTS
Paragraph
Number
Title
Page
Number
20.3
20.4
20.4.1
20.4.2
20.4.3
NMSI Configuration ........................................................................................20-33
Baud Rate Generators (BRGs).........................................................................20-35
Baud Rate Generator Configuration Registers (BRGCn)............................20-36
Autobaud Operation on a UART .................................................................20-38
UART Baud Rate Examples ........................................................................20-39
Chapter 21
Serial Communications Controllers
21.1
21.2
21.2.1
21.2.2
21.2.3
21.2.4
21.3
21.4
21.4.1
21.4.2
21.4.3
21.4.4
21.4.4.1
21.4.4.2
21.4.5
21.4.5.1
21.4.6
21.4.7
21.4.7.1
21.4.7.2
21.4.7.3
21.4.7.4
21.4.7.5
21.4.8
Features..............................................................................................................21-3
SCC Registers ....................................................................................................21-4
General SCC Mode Register (GSMR)...........................................................21-4
Protocol-Specific Mode Register (PSMR)...................................................21-10
Data Synchronization Register (DSR).........................................................21-10
Transmit-on-Demand Register (TODR)......................................................21-11
SCC Buffer Descriptors (BDs).........................................................................21-11
SCC Parameter RAM.......................................................................................21-14
Function Code Registers (RFCR and TFCR)...............................................21-16
Handling SCC Interrupts..............................................................................21-16
Initializing the SCCs....................................................................................21-17
Controlling SCC Timing with RTS, CTS, and CD......................................21-18
Synchronous Protocols.............................................................................21-18
Asynchronous Protocols ..........................................................................21-21
Digital Phase-Locked Loop (DPLL) Operation...........................................21-22
Encoding Data with a DPLL....................................................................21-24
Clock Glitch Detection.................................................................................21-25
Reconfiguring the SCCs...............................................................................21-26
General Reconfiguration Sequence for an SCC Transmitter...................21-26
Reset Sequence for an SCC Transmitter..................................................21-27
General Reconfiguration Sequence for an SCC Receiver .......................21-27
Reset Sequence for an SCC Receiver......................................................21-27
Switching Protocols .................................................................................21-27
Saving Power ...............................................................................................21-27
Chapter 22
SCC UART Mode
22.1
22.2
22.3
22.4
22.5
Features..............................................................................................................22-2
Normal Asynchronous Mode.............................................................................22-3
Synchronous Mode.............................................................................................22-3
SCC UART Parameter RAM.............................................................................22-4
Data-Handling Methods: Character- or Message-Based....................................22-5