GBA System Timer

Nut/OS System Timer implemented on the GBA. More...

Collaboration diagram for GBA System Timer:

Defines
#define	NUT_CPU_FREQ   1000000UL
#define	NUT_TICK_FREQ   1000UL
Functions
void	Timer3Entry (void *arg)
	Timer 0 interrupt entry.
void	NutRegisterTimer (void(*handler)(void *))
	Initialize system timer.
uint32_t	NutArchClockGet (int idx)
	Return the CPU clock in Hertz.
uint32_t	NutGetTickClock (void)
	Return the number of system ticks per second.
uint32_t	NutTimerMillisToTicks (uint32_t ms)
	Calculate system ticks for a given number of milliseconds.

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Detailed Description

Nut/OS System Timer implemented on the GBA.

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Define Documentation

#define NUT_CPU_FREQ   1000000UL

Referenced by NutArchClockGet().

#define NUT_TICK_FREQ   1000UL

Referenced by NutGetTickClock(), and NutTimerMillisToTicks().

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Function Documentation

void Timer3Entry

(

void *

arg

)

Timer 0 interrupt entry.

References INT_TMR3, outw, and REG_IF.

Referenced by NutRegisterTimer().

void NutRegisterTimer

(

void(*)(void *)

handler

)

Initialize system timer.

This function is automatically called by Nut/OS during system initialization.

Nut/OS uses on-chip timer 0 for its timer services. Applications should not modify any registers of this timer, but make use of the Nut/OS timer API. Timer 1 and timer 2 are available to applications.

References INT_TMR3, inw, NutRegisterIrqHandler(), outdw, outw, REG_IE, REG_IME, REG_TMR3CNT, sig_TMR3, Timer3Entry(), TMR_ENA, and TMR_IRQ_ENA.

Here is the call graph for this function:

uint32_t NutArchClockGet

(

int

idx

)

Return the CPU clock in Hertz.

Returns:

CPU clock frequency in Hertz, which is 16780000 for the GBA.

uint32_t NutGetTickClock

(

void

)

Return the number of system ticks per second.

Returns:

System tick frequency in Hertz.

References NUT_TICK_FREQ.

uint32_t NutTimerMillisToTicks

(

uint32_t

ms

)

Calculate system ticks for a given number of milliseconds.

References NUT_TICK_FREQ.