YOU CAN READ IT YES!!!  Actually in all our new products we are using 4
bits interface and it works nicely.  The busy flag will be at the first
4 bits reading. Some displays allow you to not even need to read the
last 4 bits (as the second transfer). But for more correction operation
you should read all the 8 bits (two readings of 4 bits each).  What
really happens in your case?

Wagner Lipnharski
UST Research Inc. - Orlando, Florida
http://www.ustr.net <-- 8051 site

Dale Botkin wrote:
>
> On Thu, 20 Apr 2000, Tim Hamel wrote:
>
> > Dale,
> >
> > Ok...I think I understand what you're saying...you can't read the busy flag
> > (bit 7) unless you're using the 8-bit interface? I've found something that
> > might contradict that:
> >
> > http://home.iae.nl/users/pouweha/lcd0.htm#4bit-transfer
> >
> > Apparently, you CAN read bit-7 regardless of the i/f type.
>
> In *theory*, yes.  In *practice*, we're having trouble doing so.  Every
> time I try it, the LCD goes south for the winter.  That's why we're
> working on this.  It's more than a little frustrating -- I now have a
> routine that uses 1ms delays, which works perfectly.  But now it's getting
> personal, and I wanna squash a bug.
>
> Dale
> ---
> The most exciting phrase to hear in science, the one that heralds new
> discoveries, is not "Eureka!" (I found it!) but "That's funny ..."
>                 -- Isaac Asimov