OK, so I am trying to get the Real time interrupt to work on the 9s12.
I am using a 9s12, and the gnu c compiler.
I am compiling as C++
I have a simple app, no debugger unfortuneately.
I have the serial port working so I can write data out.
I have a while loop in main that waits for some time to elapse, then will print a message out the serial port.
The RTI interrupt just increments a variable once every 1.024ms
Yes RTI clears the interrupt flag.
The timeout never happens...unless
I print to the serial port before the part where I check for timeout.
The serial port uses interrupts and works fine
So what the heck am I doing wrong?
This should work right?
( not all the code, just the impotant parts )
volatile UINT16 TimerTic;
void main(void)
{
RTICTL = 0x10; // Timer counts at 1.024 ms / tic
CRGINT_RTIE = 1; // enable interrupt
CRGFLG_RTIF = 1; // clear interrupt flag (0 writes have no effect)
...
EnableInterrupts;
UINT16 starttime = TimerTic;
for(;;)
{
//without this line TimerTic never seems to increment
Putstr("Why do I need this?\r\n");
if(TimerTic - starttime > 1000) //wait 1 second
{
PutStr("hello\r\n");
starttime = TimerTic;
}
}
// 1.024 ms clock interrupt - clear flag immediately to resume count
void Timer_Tick_ISR(void) __attribute__((interrupt))
{
CRGFLG_RTIF = 1; //CRGFLG = 0x80; // clear RTI interrupt flag
TimerTic++; // 1.024 ms, Clock tic
}
