XC912BC32CFU8 Motorola Semiconductor Products, XC912BC32CFU8 Datasheet - Page 271

• Manufacturer Part Number: XC912BC32CFU8
• Description: M68HC12B Family Data Sheet
• Manufacturer: Motorola Semiconductor Products

16.5 Interrupts
16.5.1 Interrupt Acknowledge
M68HC12B Family — Rev. 8.0
MOTOROLA
NOTE:
The msCAN12 supports four interrupt vectors mapped onto 11 different interrupt
sources, any of which can be individually masked. For details, see
msCAN12 Receiver Flag Register
Register.
Interrupts are associated directly with one or more status flags in either the
msCAN12 receiver flag register (CRFLG) or the msCAN12 transmitter control
register (CTCR). Interrupts are pending as long as one of the corresponding flags
is set. The flags in the aforementioned registers must be reset within the interrupt
handler to handshake the interrupt. The flags are reset through writing a 1 to the
corresponding bit position. A flag cannot be cleared if the respective condition still
prevails.
Bit manipulation instructions (BSET) must not be used to clear interrupt flags.
1. Transmit interrupt: At least one of the three transmit buffers is empty (not
2. Receive interrupt: A message has been successfully received and loaded
3. Wakeup interrupt: An activity on the CAN bus occurred during msCAN12
4. Error interrupt: An overrun, error, or warning condition occurred. The
scheduled) and can be loaded to schedule a message for transmission. The
empty message buffers TXE flags are set.
into the foreground receive buffer. This interrupt will be emitted immediately
after receiving the end of frame (EOF) symbol. The RXF flag is set.
internal sleep mode.
receiver flag register (CRFLG) will indicate one of these conditions:
–
–
–
–
–
–
Overrun: An overrun condition as described in
Structures
Receiver warning: The receive error counter has reached the CPU
warning limit of 96.
Transmitter warning: The transmit error counter has reached the CPU
warning limit of 96.
Receiver error passive: The receive error counter has exceeded the
error passive limit of 127 and msCAN12 has gone to error passive state.
Transmitter error passive: The transmit error counter has exceeded the
error passive limit of 127 and msCAN12 has gone to error passive state.
Bus off: The transmit error counter has exceeded 255 and msCAN12
has gone to bus-off state.
msCAN12 Controller
has occurred.
to
16.12.8 msCAN12 Transmitter Control
16.3.2 Receive
msCAN12 Controller
16.12.5
Data Sheet
Interrupts
271