[A83] Re: halt + nop
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[A83] Re: halt + nop
For those who are interested (need approximate timing and such), the
interrupt usually runs with a bit less frequency than 200hz -- on 83, it
seems to be ~160hz IIRC. It varies as the batteries are used up.
On a related note, on 85/86 the processor runs at about 5mhz maximally with
new batteries (lower as batteries die) on account of a DMA. I've been too
lazy to test this on the 83 so far, but it might be interesting to know for
troubleshooting grayscale routines.
Because of the variances, you can use the ratio of tstates per interrupt to
calculate battery life.
-----Original Message-----
From: assembly-83-bounce@lists.ticalc.org
[mailto:assembly-83-bounce@lists.ticalc.org]On Behalf Of Dan Weiss
Sent: Sunday, July 01, 2001 12:35 PM
To: assembly-83@lists.ticalc.org
Subject: [A83] Re: halt + nop
HALT waits for the next interrupt, which takes 1/200th seconds, and uses
less power than normal processing. Don't use HALT unless interrupts are
enabled (EI). HALT is often used in delays and before getting keys from the
keyboard.
NOP does nothing. Nothing. NOP is useful if you need a delay with
interrupts disabled, or when you use self modifying code. For example, if
you need to comment out code while a program is running, you replace it with
NOPs.
>From: "The one and only SUCKER!! ..." <sucker_pvn@hotmail.com>
>Reply-To: assembly-83@lists.ticalc.org
>To: assembly-83@lists.ticalc.org
>Subject: [A83] halt + nop
>Date: Sun, 01 Jul 2001 17:54:47 -0000
>
>
>What does nop do? And halt? I use halt after shutting
>my Ti-83 down so the _getk part works, but I don't
>understand what they do exactly...
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