[sci.electronics] MC6811EVB Question

pcjg7045@uxa.cso.uiuc.edu (Pramod C. John) (01/17/91)

Hello,
	I am using the MC6811EVB for a project.  Upto now I have been using 
Port C as an input, now I need to use it as an output.  It seems that although
I have set the Data Direction Register for C to all outputs (1) the port stays
as high Z inputs.  Any help with this matters would be apreciated.

Thanks,

Pramod John
email: pramod@uiuc.edu
--
Pramod John, Dept. of ECE at UIUC 
email: Pramod@uiuc.edu
"I think it would be a good idea."
  - Gandhi, when asked what he thought of Western Civilization. 

bame@hpfcbig.SDE.HP.COM (Paul Bame) (01/19/91)

> 	I am using the MC6811EVB for a project.  Upto now I have been using 
> Port C as an input, now I need to use it as an output.  It seems that although
> I have set the Data Direction Register for C to all outputs (1) the port stays
> as high Z inputs.  Any help with this matters would be apreciated.

I use the EVB "PortC" for output and have no difficulty (driving one
of those smart LCD modules) - it works as expected.  Just write 1 bits
to the DDRC (data-direction-register-C) where you want the bits to
be outputs and then write a value to PORTC.  Perhaps you could post
a code fragment which fails to drive the portC outputs, which bits(s)
you were testing electrically on portC and how.  I assume that you can
still use PORTC just fine for input which indicates the PRU and the
68HC11 startup mode are probably OK.


			-Paul "Spice is the Variety of Life"
			bame@hpfcbig.sde.hp.com	N0KCL