Xerox 560

Condition code settings:
2 3 4
Result in R
0
0
Zero
0
Negative
0
Positive
LD
LOAD DOUBLEWORD
(Doubleword index alignment)
LOAD DOUBLEWORD loads the 32 low-order bits of the
effective doubleword into register Ru1 and then loads
the 32 high-order bits of the effective doubleword into
register R.
If R is an odd value, the result in register R is the 32 high-
order bits of the effective doubleword. The condition code
settings are based on the effective doubleword, rather than
the final result in register R (see example 3, below).
Affected: (R), (Ru1), CC3, CC4
ED
32
_
63
Ru1; ED
O
_
31
R
Condition code settings:
234
o 0 Zero
- 0
Negative
o Positive
Example 1, even R field value:
Before execution After execution
ED X
'
0123456789ABCDEF' X
'
0123456789ABCDEF'
(R) xxxxxxxx X I 0 1234567
1
(Ru1) = xxxxxxxx X
'
89ABCDEF'
CC
xxxx xxlO
Example 2, odd R field value:
Before execution
After execution
ED
X
'
0123456789ABCDEF' X
'
0123456789ABCDEF'
(R)
xxxxxxxx X
'
01234567
1
CC
xxxx xx 10
Example 3, odd R field value:
Before execution After execution
ED
X 100000000 1 2345678
1
XI 00000000 1 2345678
1
(R)
xxxxxxxx
XI 00000000 I
CC
xxxx xx 10
LCH
LOAD COMPLEMENT HALFWORD
(Halfword
index alignment)
LOAD COMPLEMENT HALFWORD extends the sign of the
effective halfword 16 bit positions to the left and then loads
the 32-bit twols complement of the result into register R.
(Overflow cannot occur. )
Affected: (R), CC3, CC4
{EHSEJ-R
Condition code settings:
2 3 4 Result in R
-
0 0 Zero
- 0
Negative
o Positive
LAH LOAD ABSOLUTE HALFWORD
(Halfword
index alignment)
If the effective halfword is positive, LOAD ABSOLUTE
HALFWORD extends the sign of the effective halfword
16 bit positions to the left and then loads the 32-bit result
in
register R. If the effective halfword is negative, LAH
extends the sign of the effective halfword 16 bit positions
to
the left and then loads the 32-bit twols complement of
the result into register R. (Overflow cannot occur.)
Affected: (R), CC3, CC4
EHSE - R
Condition code settings:
2 3 4 Result in R
o 0 Zero
o Nonzero
Load/Store Instructi ons 51