[beagleboard] beaglebone - set cpu speed

i wann beaglebone cpu speed

my pc connect beaglebone with usb cable

first one for more information
i write console "cpufreq-info "

root@beaglebone:~# cpufreq-info
cpufrequtils 008: cpufreq-info (C) Dominik Brodowski 2004-2009
Report errors and bugs to cpufreq@vger.kernel.org, please.
analyzing CPU 0:
driver: omap
CPUs which run at the same hardware frequency: 0
CPUs which need to have their frequency coordinated by software: 0
maximum transition latency: 300 us.
hardware limits: 500 MHz - 500 MHz
available frequency steps: 500 MHz
available cpufreq governors: conservative, ondemand, powersave, userspace,
performance
current policy: frequency should be within 500 MHz and 500 MHz.
The governor "userspace" may decide which speed to use
within this range.
current CPU frequency is 500 MHz (asserted by call to hardware).
cpufreq stats: 500 MHz:100.00%
root@beaglebone:~# ^C
root@beaglebone:~#

later i tried this command

cpufreq-set --governor powersave
cpufreq-set -f 600MHz

If you want 600, power the board by a 5volt dc jack..

echo 275000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed

but i read cpu speed this command "cat
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq"

root@beaglebone:~# cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq
500000
root@beaglebone:~#

how can i run beaglebone 275 Mhz ?

275Mhz been disabled, specially when using the ethernet port..

Regards

i wann beaglebone cpu speed

my pc connect beaglebone with usb cable

first one for more information
i write console "cpufreq-info "

root@beaglebone:~# cpufreq-info
cpufrequtils 008: cpufreq-info © Dominik Brodowski 2004-2009
Report errors and bugs to cpufreq@vger.kernel.org, please.
analyzing CPU 0:
driver: omap
CPUs which run at the same hardware frequency: 0
CPUs which need to have their frequency coordinated by software: 0
maximum transition latency: 300 us.
hardware limits: 500 MHz - 500 MHz
available frequency steps: 500 MHz
available cpufreq governors: conservative, ondemand, powersave, userspace,
performance
current policy: frequency should be within 500 MHz and 500 MHz.
The governor “userspace” may decide which speed to use
within this range.
current CPU frequency is 500 MHz (asserted by call to hardware).
cpufreq stats: 500 MHz:100.00%
root@beaglebone:~# ^C
root@beaglebone:~#

later i tried this command

cpufreq-set --governor powersave
cpufreq-set -f 600MHz

If you want 600, power the board by a 5volt dc jack…

echo 275000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed

but i read cpu speed this command “cat
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq”

root@beaglebone:~# cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq
500000
root@beaglebone:~#

how can i run beaglebone 275 Mhz ?

275Mhz been disabled, specially when using the ethernet port…

Why has it been disabled? and it what sense (kernel, physical hardware limitation?)?

-Tripzero

Or if you want to use USB, SDRAM, etc. 275MHz has a ton of errata in the ES1.0 AM335x SoC.

The latest errata sheet ( http://www.ti.com/lit/er/sprz360b/sprz360b.pdf ) says:
“Reliability tests have shown that a logic cell used in the ARM Cortex-A8 exhibits weakness during low-voltage operation as defined by OPP50. This eliminates support for operating the ARM Cortex-A8 at the lower voltage defined by OPP50.”
(OPP50 = 275MHz)

There is a workaround to operate the AM335x on 275MHz by using OPP100 voltage levels; this however negates most of the power savings you would achieve by using OPP50 and 275MHz.

There are other issues however:
– Operation of McASP0 is not supported for OPP50.
– Operation of McASP1 is not supported for OPP50.
– Operation of GEMAC_CPSW is not supported for OPP50.

The errata sheet doesn’t mention if this means OPP50 voltage levels or OPP50 PLL frequencies, so McASP/CPSW MAY work with OPP100 voltage levels.