MC68HC05T16 Datasheet, PDF (56/128 Pages) Motorola, Inc – High-density complementary metal oxide semiconductor (HCMOS) microcontroller unit

Internal bus
Control register
MEN MIEN MSTR XMT ACKEB
Status register
MCF SELTED BBSY LOST
SRW MIF RXACKB
Interrupt
M-Bus
interrupt
Frequency
divider
register
SCL
6
SCL
control
M-Bus clock
generator
sync logic
START, STOP
detector and
arbitration
START, STOP
generator and
timing sync
TX shift
register
TX
control
8
Address
register
Address
comparator
RX shift
register
RX
control
SDA
SDA
control
Figure 6-1 M-Bus Interface Block Diagram
6.2
M-Bus Protocol
Normally, a standard communication is composed of four parts,
1) START signal,
2) slave address transmission,
3) data transfer, and
4) STOP signal.
They are described briefly in the following sections and illustrated in Figure 6-2.
MOTOROLA
6-2
M-BUS SERIAL INTERFACE
TPG
MC68HC05T16