PIC18F258 Datasheet, PDF (237/384 Pages) Microchip Technology – High Performance, 28/40-Pin Enhanced FLASH Microcontrollers with CAN

TABLE 19-3: VALUES FOR ICODE<2:0>
ICOD
<2:0>
Interrupt
Boolean Expression
000
None
ERR•WAK•TX0•TX1•TX2•RX0•
RX1
001
Error ERR
010 TXB2 ERR•TX0•TX1•TX2
011 TXB1 ERR•TX0•TX1
100 TXB0 ERR•TX0
101 RXB1 ERR•TX0•TX1•TX2•RX0•RX1
110 RXB0 ERR•TX0•TX1•TX2•RX0
Wake on ERR•TX0•TX1•TX2•RX0•RX1•
111 _{Interrupt WAK}
Key:
ERR = ERRIF * ERRIE
TX0 = TXB0IF * TXB0IE
TX1 = TXB1IF * TXB1IE
TX2 = TXB2IF * TXB2IE
RX0 = RXB0IF * RXB0IE
RX1 = RXB1IF * RXB1IE
WAK = WAKIF * WAKIE
19.13.4 MESSAGE ERROR INTERRUPT
When an error occurs during transmission or reception
of a message, the message error flag IRXIF will be set
and if the IRXIE bit is set, an interrupt will be generated.
This is intended to be used to facilitate baud rate deter-
mination when used in conjunction with Listen Only
mode.
19.13.5 BUS ACTIVITY WAKE-UP
INTERRUPT
When the PIC18FXX8 is in SLEEP mode and the Bus
Activity Wake-up Interrupt is enabled, an interrupt will
be generated, and the WAKIF bit will be set when activ-
ity is detected on the CAN bus. This interrupt causes
the PIC18FXX8 to exit SLEEP mode. The interrupt is
reset by the MCU, clearing the WAKIF bit.
PIC18FXX8
19.13.6 ERROR INTERRUPT
When the Error Interrupt is enabled, an interrupt is gen-
erated if an overflow condition occurs, or if the error
state of transmitter or receiver has changed. The error
flags in COMSTAT will indicate one of the following
conditions.
19.13.6.1 Receiver Overflow
An overflow condition occurs when the MAB has
assembled a valid received message (the message
meets the criteria of the acceptance filters) and the
receive buffer associated with the filter is not available
for loading of a new message. The associated
COMSTAT.RXnOVFL bit will be set to indicate the
overflow condition. This bit must be cleared by the
MCU.
19.13.6.2 Receiver Warning
The receive error counter has reached the MCU
warning limit of 96.
19.13.6.3 Transmitter Warning
The transmit error counter has reached the MCU
warning limit of 96.
19.13.6.4 Receiver Bus Passive
The receive error counter has exceeded the error-
passive limit of 127 and the device has gone to
error-passive state.
19.13.6.5 Transmitter Bus Passive
The transmit error counter has exceeded the error-
passive limit of 127 and the device has gone to
error- passive state.
19.13.6.6 Bus-Off
The transmit error counter has exceeded 255 and the
device has gone to bus-off state.
19.13.7 INTERRUPT ACKNOWLEDGE
Interrupts are directly associated with one or more sta-
tus flags in the PIR register. Interrupts are pending as
long as one of the flags is set. Once an interrupt flag is
set by the device, the flag can not be reset by the
microcontroller until the interrupt condition is removed.
 2002 Microchip Technology Inc.
Preliminary
DS41159B-page 235