MC68HC05BD3 Datasheet, PDF (47/112 Pages) Motorola, Inc – HCMOS microcontroller

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M-BUS SERIAL INTERFACE
M-Bus (Motorola Bus) is a two-wire, bidirectional serial bus which provides a simple, efficient way
for data exchange between devices. It is fully compatible with the I²C bus standard. This two-wire
bus minimizes the interconnection between devices and eliminates the need for address
decoders; resulting in less PCB traces and economic hardware structure. This bus is suitable for
applications requiring communications in a short distance among a number of devices. The
maximum data rate is 100Kbit/s. The maximum communication length and number of devices that
can be connected are limited by a maximum bus capacitance of 400pF.
The M-Bus system is a true multi-master bus, including arbitration to prevent data collision if two
or more masters intend to control the bus simultaneously. It may be used for rapid testing and
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alignment of end products via external connections to an assembly-line computer.
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M-Bus Interface Features
• Compatible with I²C bus standard
• Multi-master operation
• 32 software programmable serial clock frequencies
• Software selectable acknowledge bit
• Interrupt driven byte-by-byte data transfer
• Arbitration lost driven interrupt with automatic mode switching from master to slave
• Calling address identification interrupt
• Generate/detect the start, stop and acknowledge signals
• Repeated START signal generation
• Bus busy detection
MC68HC05BD3
M-BUS SERIAL INTERFACE
TPG
MOTOROLA
7-1