|
The timer appears to be running but I'm not getting any interrupts.
My hardware is very simple, I'm using a AT91SAM7X256 with an external 16Mhz Oscillator supplying the clock. I want the PLL bypassed so the core is only running at 16Mhz. I have 4 LEDS on PortB0-4 which are working fine. My build is strictly running in flash.
I'm using Rowley Crossworks and a Seggar J-Link. Adaptive Clocking:Yes Speed:2000khz
After much futzing about boot and JTAG appear very stable. Relevant Start Script Bits (mimicked in Start Up Code);
CKGR_MOR_VAL = 0x000FF002;
CKGR_MCKR_VAL1 = 0x00000000;
CKGR_MCKR_VAL2 = 0x00000001;
TargetInterface.pokeWord(0xFFFFFC20, CKGR_MOR_VAL);
TargetInterface.pokeWord(0xFFFFFC30, CKGR_MCKR_VAL1);
TargetInterface.pokeWord(0xFFFFFC30, CKGR_MCKR_VAL2);
Relevant ISR stubs; (Don't laugh... this code works on many different platforms that's why its this way.)
I am not doing anything else with the System interrupt.
AIC_SVR1 = (unsigned int)SYS ;
void SYS (void){Interrupt.ISR[INTERRUPT_VECTOR_SYS]();}
Timer Code:
#ifdef PIT_TIMER
// now bring up the hardware
// NOTE that we're using the Core Timer that runs off CCLK
DOS_Interrupt_Post(INTERRUPT_VECTOR_SYS,DOS_Timer_Interrupt);
// Enable the System Interrupt
// We will need a more comprehensive system, interrupt
// handler in the future
AIC_IDCR = 0x00000002 ; // Disable SYS interrupt
// AIC_SMR1 = 0x00000020; // system interrupt lowest priority negedge triggered
AIC_SMR1 = 0x00000060; // system interrupt lowest priority posedge triggered
// AIC_SMR1 = 0x00000000; // system interrupt lowest priority LowLevel triggered
// AIC_SMR1 = 0x00000040; // system interrupt lowest priority HighLevel triggered
// Assume we're running with a 16Mhz/16 = 1Mhz clock = 1us
// so 100us is 100 ticks
PIT_MR = PIT_MR_PITEN|PIT_MR_PITIEN|100;
AIC_ICCR = 0x00000002 ;
AIC_IECR = 0x00000002 ; // enable system interrupt
Timer.Status = PIT_PIVR ; // resets the timer and sets aside the status.
#endif
void DOS_Timer_Interrupt( void )
{
#ifdef PIT_TIMER
// Timer.Status = PIT_PIVR ; // resets the timer and sets aside the status.
AIC_EOICR = PIT_PIVR ; // clear the interrupt
#endif
DOS_Event_Handler_Post_Int(DOS_Timer_Interrupt_Handler, 0 ) ;
Timer.Ticks++ ;
}
After a while of running heres what I see in what I think are the relavent registers;
PIT_MR 0x03000064
PIT_SR 0x00000001
PIT_PIVR 0xfdd0000e
PIT_PIIR 0xfdd0000e
AIC_SMR1 0x000000020 // Prior 0, SRC 1 (Anyone else notice this is different from above?
AIC_IPR 0x000000002
AIC_IMR 0x000000002
My main loop (main context) is running with the following CPSR:
CPSR 0x600000df
Can anyone help with this?
|
Forum
