I have a TWR-K70F120M: kinetis k70 120MHz Tower System Module.
I have connected a elettric signal to PORTB and i have connected e isr handler to signal transition.
Electric signal
_____ ______ ______
| | | | | |
__| |_____| |_____| |_____ ------> PORTB
( 1 ) ( 2 ) ( 3 )
Interrupt handler is called every transition of the elettric signal ( in the figure is 1,2,3 ).
The interrupt handler is the follow code:
#define EN_ERR_SCHEDULER_INT_TOO_LONG (10)
static bool wbFlag = false; /* control the reentrant function */
__ isr void isr_handler( void )
{
/* l'interrupt precedente è durato troppo ? */
if ( wbFlag != true )
/* flag reentrant function */
wbFlag = TRUE;
}
else
vDebugPrint( EN_ERR_SCHEDULER_INT_TOO_LONG );
while(1);
wbFlag = false;
at the step ( 1 ) the program jump to the handler but not in the 2nd e third impulse. Is it possible to enable a reentrand interrupt in kinetis k70?
the setup is follow ( setup is call one time at the startup of the system ):
sllRq = 88; /*Port control module Pin Detect (Port B) */
SLONG slDiv;
/* Make sure that the IRQ is an allowable number. Right now up to 91 is
* used.
*/
if ( slIRQ > 91 )
vDebugPrint("\nERR! Invalid IRQ value passed to enable irq function!\n");
/* Determine which of the NVICISERs corresponds to the irq */
slDiv = ( slIRQ / 32 );
switch ( slDiv )
case 0x0:
NVICICPR0 = 1 << ( slIRQ % 32 );
NVICISER0 = 1 << ( slIRQ % 32 );
break;
case 0x1:
NVICICPR1 = 1 << ( slIRQ % 32 );
NVICISER1 = 1 << ( slIRQ % 32 );
case 0x2: /* program execute this case !!!!! */
NVICISER2 = 1 << ( slIRQ % 32 );
NVICICPR2 = 1 << ( slIRQ % 32 );
PORTB_PCR18 |= PORT_PCR_ISF(0) | PORT_PCR_IRQC(9) | PORT_PCR_MUX(1);
NVICIP88 = 0x00;
I need to control the reentrant interrupt because this application must check the excessive duration of the code in isr handler.
Thank you for your timely reply. You are exactly right. That solves my confusion about why my code works abnormally only for certain programs but not others. If at the time of interrupt, the core is executing a PUSH, POP, it will do that twice and mess up the stack? Debugging my code seems confirmed the stack has duplicated data when hard fault happens. Those may be data that got pushed twice. Since there are no way to write to EPSR as you said, SVC seems the only option.
Thank you for the clarification and the code that save my day.
Peng
Hi Peng,
The losing of ICI bit is less likely to be a issue. The PUSH/POP will just restart from the first transfer, from the same address. The bigger problem is the losing of the IT status. Losting the condition execution information mean the wrong instructions could get executed, or instruction that should have been skipped is executed.
Also, as you are using my Cortex-M3/M4 book, I think it worth mentioning that the errors in my books are documented in
Errors in the Definitive Guide for ARM Cortex-M book series
regards,
Joseph