Datasheet

Chapter 14. UART Modules 14-1
Chapter 14
UART Modules
This chapter describes the use of the universal asynchronous/synchronous
receiver/transmitters (UARTs) implemented on the MCF5407 and includes programming
examples. All references to UART refer to one of these modules when in UART mode as
opposed to modem mode. Particular attention is given to the UART1 implementation of a
synchronous interface that provides a controller for an 8- or 16-bit CODEC interface and
an audio CODEC ‘97 (AC ’97) digital interface.
14.1 Overview
The MCF5407 contains two independent UARTs. UART1 on the MCF5407 provides
synchronous operation and a CODEC interface for soft modem support. Each UART can
be clocked by CLKIN, eliminating the need for an external crystal. As Figure 14-1 shows,
each UART module interfaces directly to the CPU and consists of the following:
• Serial communication channel
• Programmable transmitter and receiver clock generation
• Internal channel control logic
• Interrupt control logic
Figure 14-1. Simplified Block Diagram
The serial communication channel provides a full-duplex asynchronous/synchronous
receiver and transmitter deriving an operating frequency from CLKIN or an external clock
using the timer pin. The transmitter converts parallel data from the CPU to a serial bit
stream, inserting appropriate start, stop, and parity bits. It outputs the resulting stream on
Serial
Interrupt Control
Logic
CTS
RTS
RxD
TxD
or
External clock (TIN)
Internal Channel
Control Logic
Programmable
Clock
Communications
Channel
Generation
System Integration
Module (SIM)
Interrupt
Controller
UART
CLKIN