Re: [PATCH 17/17] Add timekeeping documentation

Zachary Amsden
2010-06-16T23:59:44Z

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