At 12:07 10/19/2001 -0400, Drew Vassallo wrote:
>>>How can you expect to get a pulse resolution of .00012 if your instruction
>>>cycle time is ** .0002 ** at 20 MHz?
>>
>>The instruction cycle time is ** 0.00000005s ** for a 20Mhz clock! and
>>with both
>>the post
>>scale and pre-scale set to 16 you get a TMR2 resolution of 0.0000128s!
>
>The quadrature timing for instruction pipelining in the PIC line of products
>is a 4:1 ratio. That means a 1/20MHz * 4 = cycle time per instruction.
>
>20MHz cycle time = 200ns = .2us
Now besides black holes and other esoteric things I just wanted to set a
few things around unit modifiers and decimal numbers straight... :)
(The 200 ns basic instruction cycle time is correct for 20 MHz clock.)
200 ns = 0.2 us = 0.0002 ms = 0.0000002 s
Some interesting material every engineer should have seen at least once
(but also quite interesting for hobbyists :) can be found at the NIST
:
- International System of Units
- Guide for the Use of the International System of Units (SI)
ge
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