CCS C Software and Maintenance Offers
FAQFAQ   FAQForum Help   FAQOfficial CCS Support   SearchSearch  RegisterRegister 

ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

CCS does not monitor this forum on a regular basis.

Please do not post bug reports on this forum. Send them to CCS Technical Support

CCS, CCP, PIC18, and multiple native PWM outputs

 
Post new topic   Reply to topic    CCS Forum Index -> General CCS C Discussion
View previous topic :: View next topic  
Author Message
Confuzzed
Guest







CCS, CCP, PIC18, and multiple native PWM outputs
PostPosted: Wed Jan 05, 2005 9:21 pm     Reply with quote

Hello,

I was looking through the CCS documentation, and the documentation for the PIC18F458, which has one CCP and one ECCP module. I am aware that for a single conventional CCP module, only one PWM output is possible. For an ECCP, the datasheet suggests to me that only one INDEPENDENT PWM is possible (P1A, the remainder being variations of this, in the form of the various bridge modes) and there appears to be only one register for adjusting the duty cycle.

However, CCS allows for the setup of a CCP1 through CCP5 (setup_ccpX) for the ECCP-enabled devices, and allows for PWM1-5 (set_pwmX_duty). If I made use of these, could PWM with varying duty cycles be output simultaneously on ports P1A-P1D? Does the compiler just bit-bang this? (i.e. will the PIC be bogged down or drop the PWM during a long ISR?)

Thanks to anybody out there who can help me with this!
PCM programmer



Joined: 06 Sep 2003
Posts: 21708

View user's profile Send private message

PostPosted: Fri Jan 07, 2005 12:35 pm     Reply with quote

I didn't check the code, but I would suspect that these routines
are intended for a PIC such as the 18F4431, which has four
independent PWM modules. The 18F458 only has two PWM modules.
Look at the block diagrams in the data sheets to see this.
Display posts from previous:   
Post new topic   Reply to topic    CCS Forum Index -> General CCS C Discussion All times are GMT - 6 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group