I'm trying to play with the System Timer Module on this processor, I would like to have an interrupt every 500 us with a system clock of 120 MHz. I programmed the STM prescaler to 119 (0x77) to have 1 MHz timer clock,then I programmed the STM channel 0 compare register to 0x000001F4 (to have 500 us interrupt).What I obtained is only one interrupt is generated, then no more STM interrupr generated.
At the end of the STM ISR, I correctly clear the channel 0 interrupt flag, after that I'm no longer able to have STM interrupt.
I'm using CodeWarrior Development studio 10.6.4.
I have not seen on the MPC5644A hardware manual some particular sequence to program the registers, below my code, please can someone help me?
Best regards to you all.
STM.CR.R = 0x00007700; // Prescaler 0x77
STM.CCR0.R = 0x00000001; // Enable STM Channel 0
STM.CMP0.R = 0x000001F4; // Compare register 0 (500 us)
STM.CR.R |= 0x00000001; // Enable timer
Below the STM channel 0 ISR (now it is empty just to evaluate if the interrupt is scheduled correctly)
if (STM.CIR0.R && 0x00000001)
STM.CIR0.R = 0x00000001;