I have a processor runnin at 400 Mhz.
The function ClockCycles shows that effectively the system has
401,110,700 cycles per second. It is almost 2.5 nanosec. per cycle.
Then I used the function ClockPeriod to slow down the baseTime to fire a
pulse. The OS let me to slow down until 500,000 nanoseconds. This value
is 200,000 times the duration of a processor’s clock cycle.
Can I get a base of time smaller than 0.5 milliseconds?
Juli?n Ruiz Alfaro <jruiz@ieee.org> wrote:
I have a processor runnin at 400 Mhz.
The function ClockCycles shows that effectively the system has
401,110,700 cycles per second. It is almost 2.5 nanosec. per cycle.
Then I used the function ClockPeriod to slow down the baseTime to fire a
pulse. The OS let me to slow down until 500,000 nanoseconds. This value
is 200,000 times the duration of a processor’s clock cycle.
ClockPeriod is not based of the CPU cycle – it is based from an
external timer chip generating an interrupt at that frequency.
Can I get a base of time smaller than 0.5 milliseconds?
Nope.
-David
–
QNX Training Services
http://www.qnx.com/support/training/
Please followup in this newsgroup if you have further questions.
Hi Juli?n,
We ran into the same problem at my work. We needed a periodic event of 100
us. We got around it by using the external RTC on the board and using
interrrupt driven event. We are using a ISR process tie to the RTC to
generate a signal event to the process every 100 us. Work well.
Cheers!, Steph
“David Gibbs” <dagibbs@qnx.com> wrote in message
news:a53gei$73e$1@nntp.qnx.com…
Juli?n Ruiz Alfaro <> jruiz@ieee.org> > wrote:
I have a processor runnin at 400 Mhz.
The function ClockCycles shows that effectively the system has
401,110,700 cycles per second. It is almost 2.5 nanosec. per cycle.
Then I used the function ClockPeriod to slow down the baseTime to fire a
pulse. The OS let me to slow down until 500,000 nanoseconds. This value
is 200,000 times the duration of a processor’s clock cycle.ClockPeriod is not based of the CPU cycle – it is based from an
external timer chip generating an interrupt at that frequency.Can I get a base of time smaller than 0.5 milliseconds?
Nope.
-David
–
QNX Training Services
http://www.qnx.com/support/training/
Please followup in this newsgroup if you have further questions.