hrt_powerpc(9DKI)

NAME | SYNOPSIS | FEATURES | DESCRIPTION | RETURN VALUES | ATTRIBUTES

NAME

hrt_powerpc, hrTimerValue_powerpc, hrTimerFrequency_powerpc, hrTimerPeriod_powerpc- PowerPC High Resolution Timer API

SYNOPSIS

#include <dki/hrt/f_hrt.h>

void hrTimerValue(uint64_f * count);
void hrTimerFrequency(uint64_f * count);
void hrTimerPeriod(uint64_f * period);

FEATURES

DKI

DESCRIPTION

The High Resolution Timer API provides an access to fined grained counter source for application. This counter may be used for functions such as fine grained ordering of events or measurements of short segments of code.

The High Resolution Timer API is available from both user and microkernel execution context. Performance of a read access to the timer is in the order of memory speed, even if the access is made from a user execution context.

The API provides a read access to:

• The current timer value.

• The timer frequency.

• The difference between the minimum and the maximum of the possible timer value.

On the PowerPC architecture family, we have a resolution equal to the quarter of the bus frequency (more than one micro-second). The counter is based on the hardware 63 bits time base register.

Functions

The hrTimerValue() function attempts to read the current value form the cpu and to write it in the variable pointed by count.

The hrTimerFrequency() function attempts to write the frequency of the timer to the variable pointed by count.

The hrTimerPeriod() function attempts to write the period value (the difference beetween the maximal and the minimal value) of the timer to the variable pointed by period.

RETURN VALUES

Upon successfull completion, the value is updated. Otherwise, the variable pointed by count is set to 0.

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Interface Stability	Evolving

NAME | SYNOPSIS | FEATURES | DESCRIPTION | RETURN VALUES | ATTRIBUTES