Register lesen in C

Hab mir da mal die Hilfe vom CCS compiler gekrallt. Aber verstehen tu
ich das nicht. Wie kann ich eine Speicherzelle/Register lesen. Sollte
es doch einen einfachen Befehl dafür geben.


How do I directly read/write to internal registers?

A hardware register may be mapped to a C variable to allow direct read
and write capability to the register.  The following is an example
using the TIMER0 register:

#BYTE timer0 = 0x01

timer0= 128; //set timer0 to 128

while (timer0 ! = 200); // wait for timer0 to reach 200



Bits in registers may also be mapped as follows:

#BIT T0IF = 0x0B.2

.

.

.

while (!T0IF); //wait for timer0 interrupt



Registers may be indirectly addressed as shown in the following
example:

printf ("enter address:");

a = gethex ();

printf  ("\r\n value is %x\r\n", *a);



The compiler has a large set of built-in functions that will allow one
to perform the most common tasks with C function calls.  When possible,
it is best to use the built-in functions rather than directly write to
registers.  Register locations change between chips and some register
operations require a specific algorithm to be performed when a register
value is changed.  The compiler also takes into account known chip
errata in the implementation of the built-in functions.  For example,
it is better to do set_tris_A(0); rather than *0x85=0;

Danke hat nun geklappt mit dem lesen. Hat jemand schon einmal mit dem
Comparator interupt gearbeitet? Mit diesem Interupt kann eine sinkende
Versorgungsspannung detektiert werden.