Naming I/Os in SX/B

Clint

When defining the I/O pins in SX/B, can you name an arbitrary·group of pins? For example, could I name pins RC4 through RC 6 as a variable? I would like to be able to easily output a three bit number to a group of pins.

The structure I am referring to is something like:

··· name ·VAR· ·RC

except I would like to replace "RC" with a group of pins

I appreciate any help. I am new to the SX.

Bean

Clint,
· You can only name individual pins (RC.0) or the whole port (RC).
· To do three pin you would use "OR" and "AND" to set or clear the bits as needed:

· temp = value << 4················ ·'·Get bits in position
· temp = temp OR %1000_1111 · ' Create AND mask
· RC = RC AND temp·············· ·· ' Clear bits that are zero
· temp = temp AND %0111_0000 ' Create OR mask
· RC = RC·OR temp··················· ' Set bits that are one

· It might make more sense to just do:

· RC.4 = value.0
· RC.5 = value.1
· RC.6 = value.2

Bean.

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Post Edited (Bean (Hitt Consulting)) : 2/12/2007 5:28:36 PM GMT

Clint

Thanks for the response Bean. I think I will use this structure unless someone has a better idea.

· It might make more sense to just do:

· RC.4 = value.0
· RC.5 = value.1
· RC.6 = value.2

JonnyMac

I, too, have been down this road and agree with Bean. I usually bundle this code into a subroutine so that it's easy to call when/where I need it. You can do something like this to pass any [noparse][[/noparse]byte] variable to your port bits:

SET_PORT:
  RC.4 = __PARAM1.0
  RC.5 = __PARAM1.1
  RC.6 = __PARAM1.2
  RETURN