Communication protocol between master and slave device with register information sharing

摘要

A method for full duplex communication between master and slave devices (403, 422) coupled by a serial peripheral interface (420) includes the steps of the slave device (422) updating a status register (421) based upon an event, after which the slave device (422) transmits a communication request to the master device (403). When the master device (403) thereafter takes the slave-select line low to initiate communication, the slave device (422) automatically transmits the contents of the status register (421) over the master-in-slave-out line. At the same time, the master device (403) transmits an "empty" byte of information over the master-out-slave-in line.