MESSAGE BROADCAST IN A 1-WIRE SYSTEM

摘要

A message is simultaneously broadcast to multiple systems on a 1-wire bus. A first addressed communication session is established between a microprocessor and a first 1-wire I/O expander via a 1-wire bus, where the first 1-wire I/O expander is electrically coupled to a first system. The first 1-wire I/O expander is placed into “fast access mode”, and then removed from the 1-wire bus by opening a switch to the 1-wire bus. A second addressed communication session is established between the microprocessor and a second 1-wire I/O expander before the switch recloses, where the second 1-wire I/O expander is electrically coupled to a second system. The second 1-wire I/O expander is then placed into “fast access mode”. In response to the timer expiring and the switch reclosing, an unaddressed message is broadcast from the microprocessor to the first and second systems via the first and second 1-wire I/O expanders.

主权项

1. A modified 1-wire circuit comprising:
a microprocessor electrically coupled to a 1-wire bus, wherein the 1-wire bus has only a single data wire and a single ground wire, and wherein the 1-wire bus is initially configured to allow the microprocessor to address only one system at a time via the 1-wire bus; a first 1-wire input/output (I/O) expander, wherein the first 1-wire I/O expander electrically couples a first system to an electrical switch, wherein the electrical switch selectively couples the first 1-wire I/O expander to the 1-wire bus, wherein the electrical switch is controlled by a timer, and wherein the timer is controlled by an output of the first 1-wire I/O expander; and a second 1-wire I/O expander, wherein the second 1-wire I/O expander electrically couples a second system to the 1-wire bus.