Uploaded March 2013 | Updated September 2026, 2 weeks ago
Tishitu explains
In electronics, a subtractor can be designed using the same approach as that of an adder. The binary subtraction process is summarized below. As with an adder, in the general case of calculations on multi-bit numbers, three bits are involved in performing the subtraction for each bit of the difference: the minuend (), subtrahend (), and a borrow in from the previous (less significant) bit order position (). The outputs are the difference bit () and borrow bit . The subtractor is best understood by considering that the subtrahend and both borrow bits have negative weights, whereas the X and D bits are positive. The operation performed by the subtractor is to rewrite (which can take the values -2, -1, 0, or 1) as the sum .
Subtractors are usually implemented within a binary adder for only a small cost when using the standard two's complement notation, by providing an addition/subtraction selector to the carry-in and to invert the second operand.
(definition of two's complement negation)
The full-subtractor is a combinational circuit which is used to perform subtraction of three bits. It has three inputs, X (minuend) and Y (subtrahend) and Z (subtrahend) and two outputs D (difference) and B (borrow).
The truth table for the full subtractor is given below.
x y z D B
0 0 0 0 0
0 0 1 1 1
0 1 0 1 1
0 1 1 0 1
1 0 0 1 0
1 0 1 0 0
1 1 0 0 0
1 1 1 1 1
TISHITU
ISO: 9001-2008
RESEARCH AND CONSULTANCY CELL OF INDUSTRIAL APPLICATION
A Joint Accreditation System of Australia and New Zealand
Copyright © All Rights Reserved tishitu.org Reg No.08122629691/SSI
Accreditation No. M3111204IN
-~-~~-~~~-~~-~-
Please watch: "Lifi Communication by Arduino UNO Download Project"
youtube.com/watch?v=c4gC8dbaiZg
-~-~~-~~~-~~-~-
Tishitu explains
In electronics, a subtractor can be designed using the same approach as that of an adder. The binary subtraction process is summarized below. As with an adder, in the general case of calculations on multi-bit numbers, three bits are involved in performing the subtraction for each bit of the difference: the minuend (), subtrahend (), and a borrow in from the previous (less significant) bit order position (). The outputs are the difference bit () and borrow bit . The subtractor is best understood by considering that the subtrahend and both borrow bits have negative weights, whereas the X and D bits are positive. The operation performed by the subtractor is to rewrite (which can take the values -2, -1, 0, or 1) as the sum .
Subtractors are usually implemented within a binary adder for only a small cost when using the standard two's complement notation, by providing an addition/subtraction selector to the carry-in and to invert the second operand.
(definition of two's complement negation)
The full-subtractor is a combinational circuit which is used to perform subtraction of three bits. It has three inputs, X (minuend) and Y (subtrahend) and Z (subtrahend) and two outputs D (difference) and B (borrow).
The truth table for the full subtractor is given below.
x y z D B
0 0 0 0 0
0 0 1 1 1
0 1 0 1 1
0 1 1 0 1
1 0 0 1 0
1 0 1 0 0
1 1 0 0 0
1 1 1 1 1
TISHITU
ISO: 9001-2008
RESEARCH AND CONSULTANCY CELL OF INDUSTRIAL APPLICATION
A Joint Accreditation System of Australia and New Zealand
Copyright © All Rights Reserved tishitu.org Reg No.08122629691/SSI
Accreditation No. M3111204IN
-~-~~-~~~-~~-~-
Please watch: "Lifi Communication by Arduino UNO Download Project"
youtube.com/watch?v=c4gC8dbaiZg
-~-~~-~~~-~~-~-
