Xycom XVME-682 Manual page 38

X V M E - 6 8 2 Manual
October , 1989
6 . 5 INTERRUPTS
T h e X V M E - 6 8 2 is c a p a b l e of generat i n g i n terrupts on bot h the P C / A T b u s and VMEbus
st r uct u res. They are V M E b u s a n d Dual Port Interrupt a r e g e n e r a t e d o n t h e V M E b u s . O n the
P C / A T b u s Auxi l i a ry N o n - M a s k a b l e Interrupts (the abort button, the wat c hdog timer,
S Y S F A I L , a n d ACF AI L ) a r e g e n e r a t e d o n t h e P C / A T b u s . The next s e c t i o n s will di s cuss how
t h e s e i n terrupts are g e n e r a t e d a n d handled.
T h e X V M E - 6 8 2 B I O S m a s k s off i n terrupt l e vel s 10, 1 1, 12, a n d 1 5 duri n g its initialization
p h a s e . Before usi n g V M E b u s i n terrupts or Dual - Port m e m o r y i n terrupts, thi s m a s k must be
c h a n g e d . The fol l o wi n g c o d e will modi f y t h e m a s k i n t h e 8 2 5 9 Interrupt Control l e r located
a t I/O port address AlH;
I N A 1 , 0 A 1 H ; g e t i n terrupt mask
A N D Al, 0 1 1 0 0 0 1 1 b ; e nabl e I R Q 10, 1 1, 1 2 , and 15
O U T 0 A 1 H , Al ;write out n e w mask
NOTE
A "0" in the i n terrupt m a s k l o cati o n enabl e s the
i n terrupt, a "1" masks it.
6 . 5 . 1 VMEbus Interrupts
E a c h V M E b u s i n terrupt l i n e h a s a bit posi t i o n in the AUX_INT i n put port. VMEbus
i n terrupt l e vel 7 c o r r e s p o n d s to AUX INT bit posi t i o n 7, and so on t h rough VMEbus
i n terrupt l e vel 1 whi c h c o r r e s p o n d s to AUX INT bit posi t i o n 1. W h e n a parti c ul a r bi t in
A U X
W h e n the l o cal 8 0 2 8 6 p r o c e s s o r r e c e i v e s a n i n terrupt o n I R Q 1 0 - I R Q 1 2 or I R Q 1 5 , t h e user
p r o g r a m m u s t r e a d t h e A U X INT port to d e t e r m i n e t h e V M E b u s i n terrupt l e vel . The user
p r o g r a m m u s t perf o rm a r e a d i n t h e V M E b u s I A C K s p a c e to obt a i n t h e vect o r a n d complete
t h e V M E b u s IACK cycl e . Software shoul d c h e c k to e n s u r e the V M E b u s interrupter has
n e g a t e d its i n terrupt bef o re l e avi n g t h e I S R (i n terrupt s e r v i c e routine).
F i g u r e 6-3 s h o w s h o w V M E b u s i n terrupt l e vel s (1-7) are h a n d l e d on the XVME-682 CPU
module.
6-11
I N T i s s e t , t h e c o r r e s p o n d i n g V M E b u s i n t e r r u p t i s pending.
A r t i s a n T e c h n o l o g y G r o u p - Q u a l i t y I n s t r u m e n t a t i o n .. G u a r a n t e e d I ( 8 8 8 ) 8 8 - S O U R C E I