Messages in this thread | | | Date | Wed, 16 Jun 2010 13:59:44 -1000 | From | Zachary Amsden <> | Subject | Re: [PATCH 17/17] Add timekeeping documentation |
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On 06/15/2010 10:27 AM, Randy Dunlap wrote: > On Mon, 14 Jun 2010 21:34:19 -1000 Zachary Amsden wrote: > > >> Basic informational document about x86 timekeeping and how KVM >> is affected. >> > Nice job/information. Thanks. > > Just some typos etc. inline below. >
Thanks for all the detailed feedback! I'll include it all in the next revision. I only have one response: > >> + low, the count is halted. If the output is low when the gate is lowered, the >> + output automatically goes high (this only affects timer 2). >> + >> +Mode 3: Square Wave. This generates a sine wave. The count determines the >> > a sine wave is a square wave??? >
Actually, yes. The hardware output from timer 2 output goes through a low pass filter which effectively smooths the square wave to a sine to make the PC speaker sound somewhat less annoying. I didn't have room to depict this in the schematic. Of course, the counter output isn't directly a sine wave, and the LPF may not be all that effective, but it was the intent.
Zach
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