Re: TPU3 PWM glitch?
"trailrunner23" <[email protected]>
| Newsgroups | gmane.comp.hardware.motorola.microcontrollers |
|---|---|
| Message-ID | <[email protected]> |
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] ------------------------ Yahoo! Groups Sponsor --------------------~--> <font face=arial size=-1><a href="http://us.ard.yahoo.com/SIG=12h55sb96/M=362329.6886308.7839368.1510227/D=groups/S=1706554205:TM/Y=YAHOO/EXP=1123095171/A=2894321/R=0/SIG=11dvsfulr/*http://youthnoise.com/page.php?page_id=1992 ">Fair play? Video games influencing politics. Click and talk back!</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/