piclist 2003\02\22\025914a >
Thread: Pin won't turn off properly
www.piclist.com/techref/ubicom/devices.htm?key=sx
picon face BY : Stephen email (remove spam text)



David,

No, I do not think that the final solution is to simply add more nops...
I only gave that as a simple way to test. I also suggested writing
directly to the port in the same email, just as I have always done. You
provided example code that got the point across a little clearer. Good
job.

Read-modify-write is a common problem in any pipelined architecture and
is covered in any good college computer electronics course. Many people
however do not fully understand what it is or how it occurs, and as a
result don't know how to recognize the symptoms. The datasheet even
specifically mentions the issue, but is probably a little too soft on
the topic (to avoid scaring people?). As a result, people start blaming
the chip, when it is simply doing what it was designed to do.

I guess once someone sees a setb or clrb instruction in the datasheet,
they are just appear too tempting to pass up!! It is not immediately
obvious what actually happens in the pipeline when a setb or clrb
instruction is executed.

Cheers,
Stephen

{Original Message removed}
<002701c2da48$381891f0$6701a8c0@shollandathome> 7bit

In reply to: <5.1.0.14.2.20030221114437.00a2f210@www.rdrop.com>
See also: www.piclist.com/techref/ubicom/devices.htm?key=sx
Reply You must be a member of the piclist mailing list (not only a www.piclist.com member) to post to the piclist. This form requires JavaScript and a browser/email client that can handle form mailto: posts.
Subject (change) Pin won't turn off properly

month overview.

new search...