Hi,
I want to put the S12XEQ to sleep and wake when either when the CAN bus is energised or a CAN message is received. Before I put the micro to sleep I put the CAN tranceiver into SLEEP (High on STB pin of TJA1042).
I have asked a similar question before but have never gotten this to work. The micro would goto sleep happily, current on supply would reduce, but would never wake. I expect either CAN0 or CAN1 to wake the micro
My code looks like this when I want to start sleep.
CAN_Shutdown_OFF(); // Pull TJA1042 Stanby High = 5V = Standby
CAN0CTL0 |= WUPE; // Enable Wake Up
CAN1CTL0 |= WUPE; // WUPE allows restart from Sleep
CAN0RIER |= WUPIE; // Enable Wake Up Interrupt Enable
CAN1RIER |= WUPIE;
CAN0CTL0 |= SLPRQ; // Request sleep mode, clock continues to run
CAN1CTL0 |= SLPRQ; // Request sleep mode
while ((CAN0CTL1 & SLPAK) == 0) ; // Wait for SLPAK to == 1 Correct !
while ((CAN1CTL1 & SLPAK) == 0) ; // Wait for SLPAK to == 1
_asm ("ANDCC #$7f"); // Clear S bit. If not S is Set then STOP is disabled and it does a 2 cycle NOP
_asm ("NOP");
_asm ("STOP"); // Enter STOP mode Correct !
// Processor will now SLEEP here
_asm ("ORCC #$80"); // Set STOP bit
// And wakeup here...
CAN_Shutdown_ON(); // Pull TJA1042 Stanby low = 0V = working
I also have some code in "CAN Wake ISR", but it is much the same as above.
Can you see what I am missing?
Regards,
Wade
