Re: Linux 2.4.13-ac4

Maciej W. Rozycki
2001-10-29T17:30:12Z

On Mon, 29 Oct 2001, Henning P. Schmiedehausen wrote:

> Hm. If this is like the 8253 (ugh, way way back in the good old 8085
> days I really wired and programmed such a bugger on my CP/M system...),
> then the problem is, that the 16 bit counter is read in two 8 bit portions.
[...]
> This will happen all the time, so printing out is neither a good idea
> nor is the read problem described above an error. It is just a quirk
> in using an 8 bit chip in an 16 bit environment without being able to
> "latch" the count.

The 8254 is indeed upwards compatible to the 8253. Both provide a
counter latch command and the 8254 has an additional "read back" command,
which is also capable of latching counters.

--
+ Maciej W. Rozycki, Technical University of Gdansk, Poland +
+--------------------------------------------------------------+
+ e-mail: macro@ds2.pg.gda.pl, PGP key available +