Control Data Cyber 170 State Hardware Reference Manual page 39

Registers
Registers
The C P c o n t a i n s t h e o p e r a t i n g and s u p p o r t r e g i s t e r s d e s c r i b e d i n t h e f o l l o w i n g
paragraphs.
These r e g i s t e r s a r e l o c a t e d i n t h e operand i s s u e s e c t i o n ( f i g u r e
1-2).
The c o n t e n t s
of t h e s e r e g i s t e r s c a n be w r i t t e n i n t o memory and reloaded from
memory a s a CYBER 3.70 exchange package
by
a s i n g l e
CP
i n s t r u c t i o n
(CYBER 170
exchange jump).
Figure 2-1 shows t h e CYBER 170 exchange package.
The time a CYBER 170 exchange package r e s i d e s i n CP hardware i s c a l l e d an
execution i n t e r v a l . During t h i s i n t e r v a l , CP i n s t r u c t i o n s c a n change t h e
c o n t e n t s of X, A, B, and P r e g i s t e r s . The c o n t e n t s of o t h e r support r e g i s t e r s
change only a s a r e s u l t of a CYBER 170 exchange jump.
For f u r t h e r i n f o r m a t i o n ,
r e f e r t o CYBER 170 Exchange Jump i n c h a p t e r 5.
CM
LOCATIONS
RAC
A1 81
F LC
A2
82
N + 3
EM
FLAGS
A3 83
N
+
4
///A
RAE
A4 84
Figure 2-1. CYBER 170 Exchange Package
NO HARDWARE REGISTERS EXIST