RCA Spectra 70 - Page 145

Add Logical
(ALR) (AL)
General Description
Format
(RR)
(RX)
Condition Code
Interrupt Action
Fixed-Point
Instructions
• The operand specified by the second address (R
2
or X
2
/B
2
/D
2
)
is
logically added (32-bit unsigned)
to the operand specified by the first
address
(R
1
). The sum is placed in the general register specified by the first
address. The condition code is determined
by the relation of the sum
to a zero number and the occurrence of a carry out of the sign bit
position. An overflow on such carries is not recognized and does not set an
interrupt condition.
I (ALR) IE
Rl R2
0 7
8
11 12 15
I (ALl
5E
Rl
X
2
0 7 8
11 12 15 16
• 0 - sum is zero and no carry.
1 - sum is not zero and no carry.
2 - sum is zero with a carry.
3 - sum is not zero with a carry.
• Address error:
Addressing (RX format).
Specification (RX format).
B2 D2
19 20 31
Notes • 1. All 32 bits of the operands participate in the logical addition.
2. The operand specified by the second address is unaltered.
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