RCA 70/46 User Manual

Branch on Index High
(BXH)
General Description
Format
(RS)
Condition Code
Interrupt Action
Notes
Branching Instructions
• The operand specified by the third address (R
3
)
is added to the operand
specified by the first address (R
1
)
and the sum is algebraically compared
with the operand specified by the third address (R3), if R3 specifies an odd
register.
If R3 specifies an even register, the sum is algebraically com-
pared with R3 + 1. If the sum is low or equal, branching does not occur
and the next instruction is executed. If the sum is high, the instruction
address in the P counter is replaced by the branch address (B
2
/D
2
)
and
branching occurs.
o 7 8 11 12 15 16 19 20
31
• Unchangtd.
• None.
• 1. The sum replaces the operand specified by the first address (R
1
)
regardless of the comparison. The sum replaces (R
1
)
after the
comparison has been made.
2. Overflow is
not recognized.
3. The contents
of the register specified by R3 or R3 + 1 are unaltered.
4. When a branch occurs, the leftmost eight-bit positions of the 32-bit
P counter (ILC, CC, and mask) are unpredictable. However, the
actual condition code and program mask (hardware registers) are
unaffected by branching.
198

RCA 70/46 Specifications

General

Brand	RCA
Model	70/46
Category	Computer Hardware
Language	English