Control Data Cyber 170 State Hardware Reference Manual page 201

Instruction Lookahead Purge Control
Hardware Errors
CP/CM hardware e r r o r s a r e :
d a t a p a r i t y e r r o r s , a d d r e s s p a r i t y
errors,
and
double-bit e r r o r s . If t h e C P i s i n CYBER 170 job mode, a hardware e r r o r c a u s e s
a jump t o e x e c u t i v e s t a t e , which r e t u r n s t o C Y B E R 170 monitor mode.
If
t h e C P
i s i n C Y B E R 170 monitor mode, a hardware e r r o r causes a jump t o e x e c u t i v e
s t a t e .
The
C P h a l t s . The i n s t r u c t i o n being executed when such a f a u l t i s
d e t e c t e d
i s
n o t n e c e s s a r i l y connected with t h e f a u l t .
Conditional Software Errors
C o n d i t i o n a l software e r r o r s a r e caused by address-range e r r o r s and f l o a t i n g -
p o i n t i n f i n i t e l i n d e f i n i t e operands o r r e s u l t s . A c o n d i t i o n a l software e r r o r
causes a c t i o n , depending on b i t s s e t i n t h e E M f i e l d i n t h e c u r r e n t
CYBER 170
exchange package.
If
t h e b i t reserved f o r use with t h e s p e c i f i c type of e r r o r
i s c l e a r , t h e e r r o r i s ignored i n both CYBER 170 job and CYBER 170 monitor
modes. If t h e b i t i s s e t and t h e e r r o r occurs i n t h e CYBER 170 job mode, i t
causes an exchange t o t h e CYBER 170 monitor mode.
I f t h e b i t i s s e t
and t h e e r r o r occurs i n t h e C Y B E R 170 monitor mode, i t c a u s e s
an i n t e r r u p t t o e x e c u t i v e s t a t e .