Addition & subtraction for signed binary integers (using sign and magnitude)
πIf the binary numbers are signed then addition and subtraction can be expressed using just the
addition operation.
πTake a look at the following equations.
πX β Y = X + (- Y )
π-X β Y = (- X ) + (- Y)
πRecap: The first bit of the binary number indicates sign, 0 for positive and 1 for negative
πRules:
1. Identify the sign of each binary number [ the sign bit is excluded for the calculation]
A. If they both have the same sign
πAdd the two binaries.
πApply the sign to the result.
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πIf the binary numbers are signed then addition and subtraction can be expressed using just the
addition operation.
πTake a look at the following equations.
πX β Y = X + (- Y )
π-X β Y = (- X ) + (- Y)
πRecap: The first bit of the binary number indicates sign, 0 for positive and 1 for negative
πRules:
1. Identify the sign of each binary number [ the sign bit is excluded for the calculation]
A. If they both have the same sign
πAdd the two binaries.
πApply the sign to the result.
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3) Multiplication for unsigned integers is straight
forward,
πFind out the number of bits needed n
π Represent both numbers with n
π apply decimal multiplication rule
π apply the unsigned binary addition rule
πcut-off unnecessary bits
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forward,
πFind out the number of bits needed n
π Represent both numbers with n
π apply decimal multiplication rule
π apply the unsigned binary addition rule
πcut-off unnecessary bits
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Division Rules:
πAssumption
o n= number of bits of the divisor db1
o db2= dividend
πcut n from db2 to create a smaller binary b
π if b is less than db1 then multiply db1 by 1
πif b is greater than db1 then multiply db1 by 0
πsubtract and continue until the dividend is exhausted
πapply the subtraction rule for unsigned integers
πtrim unnecessary bits
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πAssumption
o n= number of bits of the divisor db1
o db2= dividend
πcut n from db2 to create a smaller binary b
π if b is less than db1 then multiply db1 by 1
πif b is greater than db1 then multiply db1 by 0
πsubtract and continue until the dividend is exhausted
πapply the subtraction rule for unsigned integers
πtrim unnecessary bits
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Binary Complements
Complements are used to represent negative integers in a binary form.
πPositive integers are
represented in the normal binary from.
β 1βs complement
Simply convert 0s to 1s and 1s to 0s.
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Complements are used to represent negative integers in a binary form.
πPositive integers are
represented in the normal binary from.
β 1βs complement
Simply convert 0s to 1s and 1s to 0s.
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Subtraction using 1βs complement.
πSince every negative integer can be represented uniquely subtraction can be replaced with addition. Like previously
X β Y = X + (-Y).
πRule: If there is a remainder at the end itβs added to the result.
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πSince every negative integer can be represented uniquely subtraction can be replaced with addition. Like previously
X β Y = X + (-Y).
πRule: If there is a remainder at the end itβs added to the result.
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2βs compliment
πThis is a more refined version of 1βs compliment.
πIt solves the problem of 1βs complement.
πTo find the 2βs complement of a negative integer, first find the 1βs complement the add 1.
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πThis is a more refined version of 1βs compliment.
πIt solves the problem of 1βs complement.
πTo find the 2βs complement of a negative integer, first find the 1βs complement the add 1.
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Steps in SDLC
πSDLC can be made up of multiple steps.
There is no concrete set number of steps involved.
πAround seven or eight steps appear commonly;
however, there can be anywhere from five upwards to 12.
Typically, the more steps defined in an SDLC model,
the more granular the stages are.
πIn general, an SDLC methodology follows these following steps:
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πSDLC can be made up of multiple steps.
There is no concrete set number of steps involved.
πAround seven or eight steps appear commonly;
however, there can be anywhere from five upwards to 12.
Typically, the more steps defined in an SDLC model,
the more granular the stages are.
πIn general, an SDLC methodology follows these following steps:
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Steps in SDLC
πSDLC can be made up of multiple steps.
There is no concrete set number of steps involved.
πAround seven or eight steps appear commonly;
however, there can be anywhere from five upwards to 12.
Typically, the more steps defined in an SDLC model,
the more granular the stages are.
πIn general, an SDLC methodology follows these following steps:
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πSDLC can be made up of multiple steps.
There is no concrete set number of steps involved.
πAround seven or eight steps appear commonly;
however, there can be anywhere from five upwards to 12.
Typically, the more steps defined in an SDLC model,
the more granular the stages are.
πIn general, an SDLC methodology follows these following steps:
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1.Plan and requirements:
πThe new system requirements are defined. In particular, the deficiencies in the existing system must be addressed with specific proposals for improvement. Other factors defined include needed features, functions and capabilities.
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πThe new system requirements are defined. In particular, the deficiencies in the existing system must be addressed with specific proposals for improvement. Other factors defined include needed features, functions and capabilities.
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2. Analysis:
πThe existing system is evaluated. Deficiencies are identified. This can be done by interviewing users of the system and consulting with support personnel.
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πThe existing system is evaluated. Deficiencies are identified. This can be done by interviewing users of the system and consulting with support personnel.
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3. Design:
πThe proposed system is designed. Plans are laid out concerning the physical construction, hardware, operating systems, programming, communications and security issues.
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πThe proposed system is designed. Plans are laid out concerning the physical construction, hardware, operating systems, programming, communications and security issues.
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4. Implementation
The project takes shape during the implementation phase. This phase involves the construction of the actual project result. Programmers are occupied with encoding, designers are involved in developing graphic material, contractors are building, the actual reorganisation takes place. It is during this phase that the project becomes visible to outsiders, to whom it may appear that the project has just begun. The implementation phase is the doing phase, and it is important to maintain the momentum.
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The project takes shape during the implementation phase. This phase involves the construction of the actual project result. Programmers are occupied with encoding, designers are involved in developing graphic material, contractors are building, the actual reorganisation takes place. It is during this phase that the project becomes visible to outsiders, to whom it may appear that the project has just begun. The implementation phase is the doing phase, and it is important to maintain the momentum.
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πTesting: All aspects of performance must be tested. If necessary, adjustments must be made at this stage. Tests performed by quality assurance (QA) teams may include systems integration and system testing.
πDeployment: The system is incorporated in a production environment. This can be done in various ways. The new system can be phased in, according to application or location, and the old system gradually replaced. In some cases, it may be more cost-effective to shut down the old system and implement the new system all at once.
πUpkeep and maintenance: This step involves changing and updating the system once it is in place. Hardware or software may need to be upgraded, replaced or changed in some way to better fit the needs of the end-users continuously. Users of the system should be kept up-to-date concerning the latest modifications and procedures.
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πDeployment: The system is incorporated in a production environment. This can be done in various ways. The new system can be phased in, according to application or location, and the old system gradually replaced. In some cases, it may be more cost-effective to shut down the old system and implement the new system all at once.
πUpkeep and maintenance: This step involves changing and updating the system once it is in place. Hardware or software may need to be upgraded, replaced or changed in some way to better fit the needs of the end-users continuously. Users of the system should be kept up-to-date concerning the latest modifications and procedures.
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