View previous topic :: View next topic |
Author |
Message |
vsmguy
Joined: 13 Jan 2007 Posts: 91
|
Is it possible to detect the state of SS when using the PIC |
Posted: Fri Apr 19, 2013 1:33 pm |
|
|
In a SPI slave using the PIC Hardware spi peripheral, is it possible to find out if SS went low for the current byte or was already low to begin with before the current byte was transferred, without hooking SS to a another separate PIC pin like INT?
This question is for a PIC16F87x and/or PIC18Fx550 |
|
|
temtronic
Joined: 01 Jul 2010 Posts: 9246 Location: Greensville,Ontario
|
|
Posted: Fri Apr 19, 2013 3:01 pm |
|
|
I had a look at the 18F4550 datasheet, chapter 19 - MSSP and according to what I could see in the 'block diagram' and text, there isn't any bit to read the status of *SS. It's internally tied to some logic....so I'm of the opinion you'll have to hardwire to another I/O pin to be a 'monitor'.
hth
jay |
|
|
Ttelmah
Joined: 11 Mar 2010 Posts: 19552
|
|
Posted: Sat Apr 20, 2013 2:09 am |
|
|
On most chips, the pin is still readable as a standard input logic pin, when SS is enabled.
Best Wishes |
|
|
|