MC68HC05BD3 Datasheet, PDF (60/112 Pages) Motorola, Inc – HCMOS microcontroller

is accomplished with MAL=1 and MSTA=0. If one master attempts to start transmission while the
bus is being controlled by another master, the transmission will be inhibited; the MSTA bit will be
changed from 1 to 0 without generating STOP condition; an interrupt will be generated and the
MAL bit set to indicate that the attempt to acquire the bus has failed. Considering these cases, the
slave service routine should test the MAL bit first, and software should clear the MAL bit if it is set.
7
MOTOROLA
7-14
M-BUS SERIAL INTERFACE
TPG
MC68HC05BD3