MC912DG128A Motorola, MC912DG128A Datasheet - Page 270

• Manufacturer Part Number: MC912DG128A
• Description: Microcontrollers
• Manufacturer: Motorola

External Pins
MSCAN Controller
MC68HC912DT128A Rev 2.0
270
The module is a communication controller implementing the CAN 2.0 A/
B protocol as defined in the BOSCH specification dated September
1991.
The CAN protocol was primarily, but not only, designed to be used as a
vehicle serial data bus, meeting the specific requirements of this field:
real-time processing, reliable operation in the EMI environment of a
vehicle, cost-effectiveness and required bandwidth.
msCAN12 utilizes an advanced buffer arrangement resulting in a
predictable real-time behavior and simplifies the application software.
The msCAN12 uses 2 external pins, 1 input (RxCAN) and 1 output
(TxCAN). The TxCAN output pin represents the logic level on the CAN:
0 is for a dominant state, and 1 is for a recessive state.
RxCAN is on bit 0 of Port CAN, TxCAN is on bit 1. The remaining six pins
of Port CAN are controlled by registers in the msCAN12 address space
(see
Port CAN Data Direction Register
A typical CAN system with msCAN12 is shown in
Each CAN station is connected physically to the CAN bus lines through
a transceiver chip. The transceiver is capable of driving the large current
needed for the CAN and has current protection, against defected CAN
or defected stations.
msCAN12 Port CAN Control Register (PCTLCAN)
MSCAN Controller
(DDRCAN)).
Figure 41
and
below.
msCAN12
MOTOROLA
2--mscan12