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

Problem with the ports of 18F2550

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



Joined: 20 Jul 2011
Posts: 375

View user's profile Send private message

Problem with the ports of 18F2550
PostPosted: Mon Sep 10, 2012 4:27 am     Reply with quote

Greetings! I`m using 18F2550 to control a few 74LS373 buffers. I`m using port C as data port and port b an some pins of port a like access signals. But here is the problem. I saw in the datasheet pins B3 and C1 has common function - CCP2. And this disturbs the work of my chart. When I output a specific data on port C (when I`m using PIN C1) it turns on 2 of my buffers - 1 which I have chosen and 1 extra.
What can I do to prevent this???
How to stop this extra functions??
Thanks!
Ttelmah



Joined: 11 Mar 2010
Posts: 19551

View user's profile Send private message

PostPosted: Mon Sep 10, 2012 4:38 am     Reply with quote

The CCP won't cause this.
It only ever routes to _one_ of the pins. There is no 'common function', the routing is selectable in the fuses. However provided the CCP is off, it won't do anything:

setup_ccp2(CCP_OFF);

However this is not the problem. Other things possible:

C1, is also the USB transceiver enable. USB defaults to off. You are not loading any USB code, or you are sure this is set to use the internal transceiver?.

C1, is alo one of the two pins that form the timer1 oscillator. You have got timer1, either set to use 'T1_INTERNAL', or disabled?.

You have a whisker short between the pins. Very common.

What are the other pins involved?.

Best Wishes
stoyanoff



Joined: 20 Jul 2011
Posts: 375

View user's profile Send private message

PostPosted: Mon Sep 10, 2012 4:49 am     Reply with quote

My mistake. I`m using port B as data port and ports A and C are access.
I`m using PINs - A3 and A2, C0,C1,C2,C6 and C7 as CS pins.
My chart works fine but when I output data contains only pins B3 and B4 it disturbs the chart.
I don`t use timers!
Best regards!
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