MC68HC08AZ32A Datasheet, PDF (122/312 Pages) Motorola, Inc – HCMOS Microcontroller Unit

MSCAN08 Controller (MSCAN08)
• Wakeup Interrupt: An activity on the CAN bus occurred during MSCAN08 internal sleep mode or
power-down mode (provided SLPAK = WUPIE = 1).
• Error Interrupt: An overrun, error, or warning condition occurred. The receiver flag register
(CRFLG) will indicate one of the following conditions:
– Overrun: An overrun condition as described in 11.4.2 Receive Structures has occurred.
– 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 MSCAN08 has gone to error passive state.
– Transmitter Error Passive: The transmit error counter has exceeded the error passive limit of
127 and MSCAN08 has gone to error passive state.
– Bus Off: The transmit error counter has exceeded 255 and MSCAN08 has gone to bus off state.
11.6.1 Interrupt Acknowledge
Interrupts are directly associated with one or more status flags in either the MSCAN08 receiver flag
register (CRFLG) or the MSCAN08 transmitter flag register (CTFLG). Interrupts are pending as long as
one of the corresponding flags is set. The flags in the above registers must be reset within the interrupt
handler in order 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.
NOTE
Bit manipulation instructions (BSET) shall not be used to clear interrupt
flags.
11.6.2 Interrupt Vectors
The MSCAN08 supports four interrupt vectors as shown in Table 11-1. The vector addresses and the
relative interrupt priority are defined in Table 2-1. Vector Addresses
.
Table 11-1. MSCAN08 Interrupt Vector Addresses
Function
Wakeup
Error
Interrupts
Receive
Transmit
Source
WUPIF
RWRNIF
TWRNIF
RERRIF
TERRIF
BOFFIF
OVRIF
RXF
TXE0
TXE1
TXE2
Local
Mask
WUPIE
RWRNIE
TWRNIE
RERRIE
TERRIE
BOFFIE
OVRIE
RXFIE
TXEIE0
TXEIE1
TXEIE2
Global
Mask
I Bit
MC68HC08AZ32A Data Sheet, Rev. 2
122
Freescale Semiconductor