Underclocking Beagleboard

Is it possible to underclock the latest 179$ Beagleboard?
I was thinking of using Linux Kernels cpufreq feature, any idea if this would work?


Just for the record and so people know what you are talking about, it is the Beagle-xM. And yes, cpufreq feature worksm on the -xM as long as the SW you run supports it.


Thanks for quick response.
Are there any hardware level tweaks I can use, to do the underclocking?

It is all controlled by the SW driving the internal PLLs. The external frequency is fixed at 26MHz. So, there is nothing in hardware that you need/can do.


Assuming I find a software which uses cpufreq, to underclock, how low can I underclock,
can I underclock xM from 1Ghz to 500Mhz?

Different question on the underclocking topic,
it seems like the Original BeagleBoard uses u-boot command mw to overclock
do you think I can use the same to perform underclocking?
Can you please brief me what is u-boot command internally doing with that command.


current u-boot uses "mpurate"

by default your boot.scr will have:

"mpurate=${mpurate}" in the bootargs.. (u-boot sets the variable
based on board (bx, cx, xMa))

I've you'd like set it to 500Mhz at boot instead of 1000Mhz (xMA default)


Then it'll run at 500mhz till you change it in userspace with cpufreq-utils..