Lpc2000

Quoting Paul Curtis <plc@...>:

> Hi,
>
>> There was an initiative to standardize a set of macros and library
>> routines for ISO C for Hardware access.  I havn't heard of it in a
>> while though.
>
> There is a TR for Embedded C.  It has an unweildy set of crappy macros.
> No wonder users have never heard of it, compiler vendors probably don't
> want anything to do with it.  More odeous even than C99.

That's probably what I was remembering.

>>   - Bitfield write is necessarily an RMW sequence which is
>> invalid for a lot of hardware and non-atomic on a lot of
>> processors.
>
> Actually, some ARM processors are now becoming available with bit-level
> I/O to ports.  I'm thinking here of the MAC7100 series and another
> that's coming up soon.  Writing a one or a zero to a single bit in an
> I/O port simply becomes a 32-bit write to the bit-addressed register,
> and reading that register returns a 0/1 based on the bit in the port.
> You can write all 32 bits at a time too, if you need to.

So that would be a register per bit?  32 registers to deal with a full 
32bit I/O
port (plus presumably another register for full access)?

Robert