AN2283 Freescale Semiconductor / Motorola, AN2283 Datasheet - Page 29

• Manufacturer Part Number: AN2283
• Description: Scalable Controller Area Network (MSCAN)
• Manufacturer: Freescale Semiconductor / Motorola

Receiver
Warning/Receiver
Error Passive
Interrupts
MOTOROLA
Motorola Scalable Controller Area Network (MSCAN) Interrupts
There are a total of six sources of error interrupts:
There is only one Error ISR (interrupt service routine) to service the multiple
sources of error interrupts. In the following subsections each of the six sources
of error interrupts will be described in detail and exhibit the steps needed for the
interrupt of each source. A sample piece of C code for the error ISR will be
shown after the source descriptions.
The example flowchart found in
Warning and Receive Error Passive Interrupts by the MSCAN based on the
value of the REC count. The flowchart describes the minimal steps in the
warning and error interrupt routines. Also shown is a separate routine where
the polling method is utilized to make sure the interrupt sources wanted by the
user are enabled.
As seen at the beginning of the flowchart the REC and TEC of the MSCAN are
set to 0 out of reset. The user will determine which interrupts should be enabled
based on their applications. In this case, both the Receiver Warning and
Receiver Error Interrupts are enabled to show examples of both scenarios. The
MSCAN adjusts the REC value when receive errors are detected and when
messages are received successfully.
1. Receiver Warning Interrupt
2. Transmitter Warning Interrupt
3. Receiver Error Passive Interrupt
4. Transmitter Error Passive Interrupt
5. Bus Off Interrupt
6. Overrun Interrupt
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Figure 22
illustrates generation of Receive
Error Interrupts Overview
AN2283/D
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