multi-master - это когда один master, а вокруг толпа куколдов. Да, в общем, и master куколд.
PJDL (Padded Jittering Data Link) is an asynchronous serial data link for low-data-rate applications that supports both master-slave and multi-master communication over a common conductive medium. PJDL can be easily implemented on limited microcontrollers with low clock accuracy and can operate directly using a single input-output pin.