On Feb 12, 2006, at 1:21 PM, Rick Mann wrote:
If starting from scratch I usually write something like this:
#define TXCIE0_b (6)
#define TXCIE0_m (1<<TXCIE0_b)
Traditionally, Mac OS APIs were written like this, giving both a
bit number and a mask value.
That is likely where I picked up the habit.
However, the technique doesn't let you explicitly show which bits
you want to be zero.
This loops us back around to Larry's concern about the ! not doing
what he expected. OR all the _m's that you want to set to ones, then
AND ~TXCIE0_m's to clear.
What I'd really rather have is the entire UART abstracted in a struct
with overlapping unions and bitfields. IIRC not all the relevant
registers were grouped together, and UART0 and UART1's registers were
in wildly different places.
Makes for a terribly huge file and atrocious register names but this
is exactly what Motorola/Freescale/Metrowerks did for the HCS12 family.
--
David Kelly N4HHE, [EMAIL PROTECTED]
========================================================================
Whom computers would destroy, they must first drive mad.
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