On 2012-08-24, Grant Edwards <grant.b.edwa...@gmail.com> wrote:
> On many processors doing things like clearing an interrupt flag is
> done by writing a 1 to the bit you wish to clear. That makes the
> hardware implementation much simpler and it lets you use a C statement
> like:
>
> P1IFG = P1_PWR_SW;
>
> Which is much less likely to be a non-atomic operation.
I've always been a bit baffled why TI didn't follow the normal "write
1's to clear interrupt flags" paradigm. Instead, they chose something
that's more complex for both software and hardware.
IIRC, some of the early processors had bugs in the "special case"
handling for the BIC instruction, and clearing interupt flags in some
registers _didn't_ work reliably.
--
Grant Edwards grant.b.edwards Yow! JAPAN is a WONDERFUL
at planet -- I wonder if we'll
gmail.com ever reach their level of
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