PIC18F258 MICROCHIP [Microchip Technology], PIC18F258 Datasheet - Page 229

• Manufacturer Part Number: PIC18F258
• Description: High Performance, 28/40-Pin Enhanced FLASH Microcontrollers with CAN
• Manufacturer: MICROCHIP [Microchip Technology]

FIGURE 19-5:
 2002 Microchip Technology Inc.
Move Message into RXB0
according to which Filter
Criteria was met
Set RXRDY = 1
Set FILHIT <0>
RXFUL = 0?
RXIE = 1?
MESSAGE RECEPTION FLOW CHART
Is
Is
Yes
No
The RXFUL bit determines if the
receive register is empty and able
to accept a new message.
No
Yes
Generate Overrun Error:
Set RXB0OVFL
Generate
Frame
Error
RX0DBEN = 1?
Yes, meets criteria
for RXBO
Is
The RXB0DBEN bit determines if
RXB0 can rollover into RXB1 if it is
full.
Set CANSTAT <3:0> according
to which Receive Buffer the
Message was loaded into
No
Preliminary
Message Assembly Buffer (MAB)
No
No
Begin Loading Message into
ERRIE = 1?
a Filter Criteria?
Generate
Interrupt
Yes
Identifier meets
Yes
Received?
Message?
Go to Start
Message
Message
Is
Start of
Detect
Valid
Start
Yes
Yes
Generate Overrun Error:
Set RXB1OVFL
No
Go to Start
No
Yes, meets criteria
for RXB1
Yes
No
Move Message into RXB1
according to which Filter
PIC18FXX8
Set FILHIT <2:0>
Criteria was met
Set RXRDY = 1
RXFUL = 0?
Yes
RXIE = 1?
Is
Is
No
DS41159B-page 227