MC912DG128A Motorola, MC912DG128A Datasheet - Page 285

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

msCAN12
POWER_DOWN
Mode
Programmable
Wake-Up Function
Timer Link
17-mscan12
MOTOROLA
The msCAN12 is in POWER_DOWN mode when
When entering the POWER_DOWN mode, the msCAN12 immediately
stops all ongoing transmissions and receptions, potentially causing CAN
protocol violations. The user is responsible to take care that the
msCAN12 is not active when POWER_DOWN mode is entered. The
recommended procedure is to bring the msCAN12 into SLEEP mode
before the STOP instruction (or the WAI instruction, if CSWAI is set) is
executed.
To protect the CAN bus system from fatal consequences of violations to
above rule, the msCAN12 will drive the TxCAN pin into recessive state.
In POWER_DOWN mode, no registers can be accessed.
The msCAN12 can be programmed to apply a low-pass filter function to
the RxCAN input line while in SLEEP mode (see control bit WUPM in the
module control register,
This feature can be used to protect the msCAN12 from wake-up due to
short glitches on the CAN bus lines. Such glitches can result from
electromagnetic inference within noisy environments.
The msCAN12 will generate a timer signal whenever a valid frame has
been received. Because the CAN specification defines a frame to be
valid if no errors occurred before the EOF field has been transmitted
successfully, the timer signal will be generated right after the EOF. A
pulse of one bit time is generated. As the msCAN12 receiver engine
receives also the frames being sent by itself, a timer signal will also be
generated after a successful transmission.
•
•
the CPU is in STOP mode or
the CPU is in WAIT mode and the CSWAI bit is set (see
Module Control Register
MSCAN Controller
msCAN12 Module Control Register
(CMCR0)).
MC68HC912DT128A Rev 2.0
MSCAN Controller
(CMCR0)).
msCAN12
Timer Link
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