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 support@ccsinfo.com
SPI Mode for the ADS8509

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



Joined: 10 Aug 2009
Posts: 6

View user's profile Send private message

SPI Mode for the ADS8509
PostPosted: Mon Mar 22, 2010 10:05 am     Reply with quote
Hello everybody, someone could help me to identify the operating mode SPI for the ADS8509?

http://focus.ti.com/lit/ds/symlink/ads8509.pdf
PCM programmer



Joined: 06 Sep 2003
Posts: 21708

View user's profile Send private message

PostPosted: Mon Mar 22, 2010 12:49 pm     Reply with quote
To try to make the ADS8509 interface be as SPI-like as possible, I think
you want to use the method shown in this diagram in the data sheet:
Quote:

Figure 4. Read After Conversion (Discontinuous External DATACLK)

That diagram shows that data changes on the rising edge of the external
clock, so presumably you would sample (in the PIC) on the falling edge.

Also, on page 17 of the data sheet, it says:
Quote:

In this discontinuous external clock mode with no SYNC, 16 clocks are
necessary to read the data on the falling edge.

This means data is sampled (by the PIC) on the falling edge.
That's confirmed.

Figure 4 in the data sheet also shows that the external clock idles at a
low level.

Now look at the SPI modes diagram on this page:
http://www.totalphase.com/support/kb/10045/#modes
It's clear that Mode 1 idles at a low level and samples on the falling edge,
so that's the mode to use.
sir_jfreyes



Joined: 10 Aug 2009
Posts: 6

View user's profile Send private message

PostPosted: Wed Mar 24, 2010 10:55 pm     Reply with quote
Thanks a lot for help me and take time for do it.
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