AMX 86 ajflagrd, ajflagrddi ajflagrd, ajflagrddi ajflagwr ajflagwr

AMX 86 Procedures

DAK

235

ajflagrd, ajflagrddi ajflagrd, ajflagrddiajflagwr ajflagwr

Purpose Read Processor Flags

Read Processor Flags and Disable Interrupts

Write Processor Flags

Used by n Task n IS P n Timer Procedure n Restart Procedure n Exit Procedure

Setup unsigned int flags;

flags = ajflagrd(); /* Read current flags */

flags = ajflagrddi(); /* Read current flags and */

/* then inhibit interrupts */

ajflagwr(flags); /* Restore flags */

Results Ajflagrd and ajflagrddi return the state of the processor status register

(FLAGS) at the time of the call.

Upon return from ajflagrddi, interrupts are disabled.

Upon return from ajflagrd, interrupts are untouched.

Ajflagwr writes parameter flags to the processor status register (FLAGS)

and returns nothing.

Upon return from ajflagwr, interrupts are enabled or disabled according

to the state of the interrupt enable flag (IF) in parameter flags.

Restrictions Interrupts should be enabled within a short time after they are disabled or

system performance will be degraded.

Note The assembly language sequence for ajflagrd and ajflagrddi is:

PUSHF

POP AX ;AX = processor flags

CLI ;Omit for ajflagrd

The assembly language sequence for ajflagwr is:

PUSH <flags>

POPF

Note These functions can be called from your main() program before AMX has

been launched or after AMX has been shut down.