AN1753 Datasheet, PDF (1/22 Pages) STMicroelectronics – Software UART using ST7LITE0 12-bit autoreload timer

AN1753
Application note
Software UART using ST7LITE0 12-bit autoreload timer
Introduction
This application note describes a software implementation of a Universal Asynchronous
Receiver/Transmitter (UART). This can be used on devices with no on-chip SCI peripheral.
In this example, a software UART is implemented for the ST7LITE0, using the 12-bit
Autoreload timer and two I/O ports for asynchronous receive and transmit. The UART
software provides the following features:
• Half-duplex operation
• Asynchronous operation
• Flexible data formats (7 or 8 data bits, 1 or 2 stop bits)
• Baud rate: 2400 to 19200 baud
To test this interrupt-driven software UART, you can use the “Hyperterminal” application
running on a Windows PC.
The program code is quite small (357 bytes) and can easily be adapted to specific
application requirements.
Table 1 lists the microcontrollers and software concerned by this application note.
Type
Microcontrollers
Software
Table 1. Applicable products and software
Part numbers or product categories
ST7LITE02Y0, ST7LITE05Y0, ST7LITE09Y0
STSW-ST7094
March 2013
DocID9986 Rev 2
1/22
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