MPC5644A - SWT interrupt not available in INTC?

[kaifalkenberg]

Hi,

according to the datasheet the MPC5644A provides a SWT (Software Watchdog Timer) interrupt. However, the datasheet also states in chapter 15.2.2 that there a 0 watchdog interrupts available to the interrupt controller. How can I make use of the SWT interrupt?

Best regards

[davidtosenovjan]

Hi, I am attaching presentation slide explaining how it is routed to core exception. Also I am attaching example code for MPC5634M device, where it is implemented similar way.

[kaifalkenberg]

Hi David,

thank you for your quick reply! Following the powerpoint and the RM I have done the following:

• set SIU.DIRER.B.NMISEL0 = 0x01U;
• set SIU.IREER.B.NMIRE0   = 0x01U;
• set the ITR bit in SWT.MCR (SWT.MCR.R = 0xFF00007BU)
• implemented an exception handler for IVOR0

The behaviour is now the same as before: The watchdog triggers a reset, but the ISR is never reached. Any ideas on what I might be missing?

[davidtosenovjan · Accepted solution]

It is needed to follow sequence I have shown in the attached example (main routine).

Enable IVOR0 by MSR[CE], set timeout, in ESR service watchdog, otherwise in second timeout SWT resets the device.