In SX Microcontrollers, SX/B Compiler and SX-Key Tool, rodneymc wrote:

I'm running out of 'cycle' space in my interrupt on the SX28.  (RTCC Overflow, by about 16 clocks w/ NOPRESERVE according to SX/SIM).

Other than increasing Frequency, adjusting the cycles and trying to optimize code, can I use an SX48 w/ the software timers to act as RTCC of 1024 instead of 255 to gain more interrupt 'cycle' space (just a tad more?) 

Using the prescaler won't work right, as it 'reduces' the code space the interrupt can support, effectivly slowing it down, right??

So, the maximum to maintain a Midi Baud rate (31250) be:

<UL>
* 50MHz 4us = 200 Cycles of code (+ overhead) Rate = 250000

* 50MHz 4us = 100 Cycles of code (+ overhead) Rate = 250000 w/ RTCC of 2

* 20MHz 2us = 160 Cycles of code (+ overhead) Rate = 125000
</UL>
Anything else would requre RTCC to be &gt; 255. 

Thanks!

Rodney

---------- End of Message ----------


You can view the post on-line at:
http://forums.parallax.com/forums/default.aspx?f=7&p=1&m=104346#m284994

Need assistance? Send an email to the Forum Administrator at forumadmin@parallax.com

The Parallax Forums are powered by dotNetBB Forums, copyright 2002-2008 (http://www.dotNetBB.com)