Using a UART to Implement a 1-Wire Bus Master

Abstract: This application note explains how to use a microprocessor's UART to implement a 1-Wire® bus master. It includes an explanation of the required electrical interface, UART configuration, and timing relationship between UART and 1-Wire signals. The flexibility offered in setting up UART byte timing allows straightforward implementation of 1-Wire time slots as well as the reset and presence detect pulses. With the inclusion of deep transmit and receive FIFOs, several byte values can be transferred on the 1-Wire bus with just a few clock cycles per bit required from the main processor.
Using a UART to Implement a 1-Wire Bus Master
Sep 10, 2002

Abstract: This application note explains how to use a microprocessor's UART to implement a 1-Wire bus master. It includes an
explanation of the required electrical interface, UART configuration, and timing relationship between UART and 1-Wire signals. The
flexibility offered in setting up UART byte timing allows straightforward implementation of 1-Wire time slots as well as the reset and
presence detect pulses. With the inclusion of deep transmit and receive FIFOs, several byte values can be transferred on the 1-
Wire bus with just a few clock cycles per bit required from the main processor.


Introduction
1-Wire devices provide economical solutions for identification, memory, time keeping, measurement and control. The 1-Wire data