According to http://www.ti.com/lit/ds/sprs717h/sprs717h.pdf, the AM3358 supports three frequencies: 1000, 800, and 600 MHz (table 3-1). The BeagleBone Black is equipped with the SoC am3358bzcz100. According to paragraph 5.4, the so called Operating Performance Points for this SoC are (table 5-7):
VDD_MPU OPP ARM (A8) ------------- -------- Nitro 1000 MHz Turbo 800 MHz OPP100 600 MHz OPP50 300 MHz Some peripherals and features have limited support when the device is operating in OPP50 (paragraph 7.3), like unsupported DDR3 (much to my believe the BBB uses) and reduced DDR2 performance. Then 300 MHz runs the BeagleBone in a limited way? This is not what we've seen here. So I'm still confused why the AM3358 does not support 300 MHz (and BTW the AM3352 does, 300, 600, and 1000). Mark Op maandag 21 september 2015 21:00:40 UTC+2 schreef William Hermans: > > I do not know the technical reasons how, but I do know that 300Mhz has > been the low end of cpufreq-set for a good long time now. Which is what the > ondemand governor uses when CPU load is less than ~66%. Otherwise the > processor can go up to 1Ghz when CPU load is greater than ~66%. > > Anyway, I've been using ondemand mostly for well over a year I believe. No > ill effects on my circuitco A5A, or element 14 REV C's( we have 2 A5A's and > 3 REV C's ). > > On Mon, Sep 21, 2015 at 11:44 AM, Mark Ruys <[email protected] > <javascript:>> wrote: > >> I'm confused how the BBB can run on 300 MHz. >> >> The BeagleBone has a AM3358 processor, and according to >> http://www.ti.com/lit/ds/symlink/am3358.pdf, it supports 600, 800, and >> 1000 Mhz, not 300 MHz. Still, using tools like cpufreq-set, you can set the >> frequency to 300. The power usage drops indeed and the CPU power is lowered >> pro rato. >> >> Does someone what happens? Is 300 a frequency which is unsupported by >> TI's AM3358? If so, are there any risks? >> >> Thanks, Mark >> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> > > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
