Chapter 23

UART Modules

This chapter describes the use of the universal asynchronous receiver/transmitters (UARTs) implemented on the MCF5282 and includes programming examples.

NOTE

The designation “n” is used throughout this section to refer to registers or signals associated with one of the three identical UART modules: UART0, UART1, or UART2.

23.1 Overview

The MCF5282 contains three independent UARTs. Each UART can be clocked by the system clock, eliminating the need for an external UART clock. As Figure 23-1shows, each UART module interfaces directly to the CPU and consists of the following:

Serial communication channel

Programmable clock generation

Internal channel control logic

Interrupt control logic

UART

System Control

Module (SCM)

Interrupt

Controller

Internal Channel Control Logic

Interrupt Control

Logic

Serial

Communications

Channel

Programmable

Clock

Generation

UCTS

URTS

URXD

UTXD

System Clock or

External clock (DTINn)

Figure 23-1. Simplified Block Diagram

NOTE

UART0 can be clocked by the DTIN0 pin. UART1 can be clocked by the DTIN1 pin, and UART2 can be clocked by DTIN2.

MOTOROLA

Chapter 23. UART Modules

23-1

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Motorola MCF5281, MCF5282 user manual Uart, Ucts Urts Urxd Utxd