mcf5272 Freescale Semiconductor, Inc, mcf5272 Datasheet - Page 361

• Manufacturer Part Number: mcf5272
• Description: Mcf5272 Coldfire Integrated Microprocessor User
• Manufacturer: Freescale Semiconductor, Inc

MOTOROLA
Chapter 16
UART Modules
This
receiver/transmitters (UARTs) implemented on the MCF5272 and includes programming
examples. All references to UART refer to one of these modules.
16.1 Overview
The MCF5272 contains two independent UARTs. Each UART can be clocked by either
URT_CLK or CLKIN, eliminating the need for an external crystal. As Figure 16-1 shows,
each UART module interfaces directly to the CPU and consists of the following:
The serial communication channel provides a full-duplex asynchronous/synchronous
receiver and transmitter deriving an operating frequency from CLKIN or an external clock
of the correct frequency (URT_CLK). 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 the channel transmitter serial data output (TxD). See Section 16.5.2.1,
“Transmitting.”
The receiver converts serial data from the channel receiver serial data input (RxD) to
parallel format, checks for a start, stop, and parity bits, or break conditions, and transfers
the assembled character onto the bus during read operations. The receiver may be polled-
or interrupt-driven. See Section 16.5.2.2, “Receiver.”
• Serial communication channel
• Programmable transmitter and receiver clock generation
• Internal channel control logic
• Interrupt control logic
chapter
System Integration
Module (SIM)
Controller
Interrupt
describes
Figure 16-1. Simplified Block Diagram
the
Internal Channel
Interrupt Control
Control Logic
Chapter 16. UART Modules
Logic
use
of
UART
the
Communications
Programmable
Generation
Channel
universal
Clock
Serial
asynchronous/synchronous
URT_CTS
URT_RTS
URT_RxD
URT_TxD
CLKIN
or
External clock (URT_CLK)
16-1