hollis@austin.ibm.com wrote:
Would you say poking the 8259 directly is more "right" than using 0xbffffff0
(or equivalent)?
Both methods are equally right. However, the polling method requires knowledge
only of the 8259s, which is required anyway, while the other method requires
knowledge of the interrupt acknowledge mechanism. It is also possible for
somebody to design a machine with 8259s without any interrupt acknowledge
mechanism at all, the 8259 datasheet will tell you that it has been designed
for such applications as well.
MS
** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/
On Wed, 7 Nov 2001, Michael Sokolov wrote:
hollis@austin.ibm.com wrote:
quoted
Would you say poking the 8259 directly is more "right" than using 0xbffffff0
(or equivalent)?
Both methods are equally right. However, the polling method requires knowledge
only of the 8259s, which is required anyway, while the other method requires
knowledge of the interrupt acknowledge mechanism. It is also possible for
somebody to design a machine with 8259s without any interrupt acknowledge
mechanism at all, the 8259 datasheet will tell you that it has been designed
for such applications as well.
But because you have 2 cascaded i8259s it's more complex to poll both i8259s
than to read the single magic interrupt acknowledge register.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/