DL205 User Manual, 4th Edition, Rev. D
5-93
Chapter 5: Standard RLL Instructions
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A
B
C
D
Subtract Real (SUBR)
The Subtract Real is a 32-bit instruction that subtracts a real
number, which is either two consecutive V-memory locations or
a 32-bit constant, from a real number in the accumulator. The
result is a 32-bit real number that resides in the accumulator. Both
numbers must be Real data type (IEEE floating point format).
NOTE: Status flags are valid only until another instruction uses the same flag.
NOTE: The current HPP does not support real number entry with automatic conversion to the 32-bit IEEE
format. You must use DirectSOFT for this feature.
SUBR
A aaa
230
240
250-1
260
129 -- 127 =2
(Hex number)
Mantissa (23bits)Sign Bit
41B00000
000041B0
(SUBR)
(Accumulator)
4170 0 000
_
000040E0
Acc.
22
(decimal)
_
15
7
1.11 x2(exp 2) = 111.binary= 7 decimal128 +1= 129
Exponent (8 bits)
DirectSOFT
Load the real number
22.0 into the accumulator.
Subtract the real number
15.0 from the accumulator
contents, which is in real
number format.
Copy the result in the
accumulator to V1400
and V1401.
Discrete Bit Flags Description
SP63 On when the result of the instruction causes the value in the accumulator to be zero
SP70 On anytime the value in the accumulator is negative
SP71 On anytime the V-memory specified by a pointer (P) is not valid
SP72 On anytime the value in the accumulator is an invalid floating point number
SP73 On when a signed addition or subtraction results in an incorrect sign bit
SP74 On anytime a floating point math operation results in an underflow error
SP75 On when a real number instruction is executed and a non-real number was encountered
Operand Data Type DL250-1 Range DL260 Range
A aaa aaa
V-memory V All. (See page 3-55) All. (See page 3-56)
Pointer P All V-memory (See page 3-55) All V-memory (See page 3-56)
Constant R
-3.402823E+038 to
+ 3.402823E+038
-3.402823E+038 to
+ 3.402823E+038
DS Used
HPP N/A
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