RE: Re: TPU3 PWM glitch?
"Schroeder, Steven A." <[email protected]>
| Newsgroups | gmane.comp.hardware.motorola.microcontrollers |
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| Message-ID | <631DE9E22D35CE409D3AD8844336212607B70D25@galmismb02.napa.ad.etn.com> |
Just PWMHI. Steve -----Original Message----- From: trailrunner23 [mailto:[email protected]] Sent: Wednesday, August 03, 2005 12:52 PM To: [email protected] Subject: [MPC500] Re: TPU3 PWM glitch? According the TPU documentation, you may get a glitch if you request an "immediate update" via HSR %01, but if you simply write to PWMHI, the duty cycle won't change until the end of the current period and you will not get a glitch. The docs say that this should be for 0% or 100%. Are you writing to PWHMI and also to HSR to request immediate update, or are you simply writing to PWMHI? Joe Pasquariello --- In [email protected], "Schroeder, Steven A." <StevenASchroeder@e...> wrote: > We are using a TPU3 channel in the MPC563 to generate a 4kHz PWM signal. Updating the duty cycle is accomplished by simply writing a new PWMHI value and it operates very well. Until now. When the duty cycle first becomes 0% we write 0 to PWMHI. The first cycle at 0% outputs a 550ns pulse; after that it stays low. > > The problem is that the device being driven does not like narrow pulses such as this. Has anyone seen this before? > > Steve > > > [Non-text portions of this message have been removed] ----------------------------------------------------------- To learn more about Freescale Microcontrollers, please visit http://www.freescale.com/mcu Yahoo! Groups Links ------------------------ Yahoo! Groups Sponsor --------------------~--> <font face=arial size=-1><a href="http://us.ard.yahoo.com/SIG=12h3catpg/M=362335.6886445.7839731.1510227/D=groups/S=1706554205:TM/Y=YAHOO/EXP=1123095558/A=2894361/R=0/SIG=13jmebhbo/*http://www.networkforgood.org/topics/education/digitaldivide/?source=YAHOO&cmpgn=GRP&RTP=http://groups.yahoo.com/">In low income neighborhoods, 84% do not own computers. At Network for Good, help bridge the Digital Divide!</a>.</font> --------------------------------------------------------------------~-> ----------------------------------------------------------- To learn more about Freescale Microcontrollers, please visit http://www.freescale.com/mcu Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/MPC500/ <*> To unsubscribe from this group, send an email to: [email protected] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/