摘要 |
A single-wire digital interface for receiving digital data as a stream of pulses, with '1' and '0' logic levels represented with pulses having "first" and "second" pulse widths, respectively. A low-pass filter produces an output that increases at a known rate for the duration of a received data pulse, and a comparator produces an output that toggles when the filter output exceeds a predetermined threshold. A clock edge is generated when a received pulse terminates; the clock and comparator outputs are provided to a latch circuit. The interface latches a '1' when the received pulse's width is equal to the "first" pulse width, and latches a '0' when the received pulse's width is equal to the "second" pulse width. Data is preferably preceded by a "start-of-packet" (SOP) bit pattern and followed with a "end-of-packet" (EOP) bit pattern.
|