Datasheet

MSCAN
MC9S12DP256 — Revision 1.1
MSCAN
Interrupt
Acknowledge
Interrupts are directly associated with one or more status flags in either
the MSCAN Receiver Flag Register (CANRFLG) or the MSCAN
Transmitter Flag Register (CANTFLG). 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 to handshake the interrupt.
The flags are reset by writing a ‘1’ to the corresponding bit position. A
flag cannot be cleared if the respective condition still prevails.
CAUTION: It must be guaranteed that the CPU only clears the bit causing the
current interrupt. For this reason, bit manipulation instructions (BSET)
must not be used to clear interrupt flags. These instructions may cause
accidental clearing of interrupt flags which are set after entering the
current interrupt service routine.
Interrupt Sources The MSCAN supports four interrupt functions as shown in Table 95.
NOTE: The vector addresses and the relative interrupt priority are determined
at the MCU level.
Recovery from
STOP or WAIT
The MSCAN can recover from STOP or WAIT via the wake-up interrupt.
This interrupt can only occur if the MSCAN is in sleep mode (SLPRQ=1
and SLPAK=1), the wake-up option is enabled (WUPE=1) and the
wake-up interrupt is enabled (WUPIE=1).
Table 95 MSCAN Interrupt Sources
Interrupt Function Interrupt Flag
Local
Enable
Global
(CCR)
Mask
Wake-Up WUPIF WUPIE
I Bit
Error
Interrupts
CSCIF CSCIE
OVRIF OVRIE
Receive RXF RXFIE
Transmit
TXE0 TXEIE0
TXE1 TXEIE1
TXE2 TXEIE2
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Freescale Semiconductor, Inc.
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