Re: [avr-chat] HELP! mega128 USART receive restarts execution

[David Kelly]

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, address@hidden
========================================================================
Whom computers would destroy, they must first drive mad.