RCA Spectra 70 User Manual

Shift Right Double
(SRDA)
General Description
Format
(RS)
Condition Code
Interrupt Action
Notes
Fixed-Point
Instructions
• The integer portion of the double-word operand specified by the first
address (R
1
)
and the first address plus one is shifted right the number of
positions specified by the second address (BdD
2
). The first address (R)
specifies an even-numbered register of an even/odd pair that contains the
63-bit integer to be shifted. The second address is used as a count and not
to address data. The low-order six bits of the second address constitute the
count. The remaining bits are ignored.
8E
o
7 8
11 12
15 16
• 0 - result is zero.
1 - result is less than zero.
2 - result is greater than zero.
3
-not used.
• Address error:
Specification.
19 20
31
• 1. All 63 bit positions of the integer are shifted. The sign bit in the
leftmost position of the even-numbered register is not altered. This
sign bit is propagated through the positions vacated in the left end
of the double-word operand. The bits shifted out to the right are lost.
2. A shift count of zero provides a double-word sign and magnitude
check.
153

RCA Spectra 70 Specifications

General

Brand	RCA
Model	Spectra 70
Category	Computer Hardware
Language	English