UART Modules
MCF5272 ColdFire
®
Integrated Microprocessor User’s Manual, Rev. 3
16-2
Freescale Semiconductor
16.2
Serial Module Overview
The MCF5272 contains two independent UART modules, whose features are as follows:
•
Each clocked by either URT_CLK or CLKIN, eliminating a need for an external crystal
•
Full-duplex asynchronous/synchronous receiver/transmitter channel
•
24-byte FIFO receiver
— CTS receiver FIFO control
— Receiver FIFO timeout
•
24-byte FIFO transmitter
•
Independently programmable receiver and transmitter clock sources
•
Programmable data format:
— 5–8 data bits plus parity
— Odd, even, no parity, or force parity
— One, one-and-a-half, or two stop bits
•
Each channel programmable to normal (full-duplex), automatic echo, local loop-back, or remote
loop-back mode
•
Automatic wake-up mode for multidrop applications
•
Eight maskable interrupt conditions
•
Parity, framing, and overrun error detection
•
False-start bit detection
•
Line-break detection and generation
•
Detection of breaks originating in the middle of a character
•
Start/end break interrupt/status
•
Autobaud capability
The MCF5272 UART modules are identical to those on other ColdFire devices, such as the MCF5206e,
with the following exceptions:
•
The MCF5272 receiver and transmitter FIFOs have been expanded to 24 bytes.
•
Interrupts can be programmed to occur at various levels of FIFO fullness on both the receiver and
transmitter.
•
Autobaud capability has been added to automatically calculate the character transmission rate from
the first received character.
•
Registers have been added to increase accuracy in clock generation.
16.3
Register Descriptions
This section contains a detailed description of each register and its specific function. Flowcharts in
,” describe basic UART module programming. The operation of the UART
module is controlled by writing control bytes into the appropriate registers.
for UART module registers.
