Computer Knowledge
Digital Logic and Microprocessors
735 Questions
Digital logic and microprocessors form the core of computer science, covering logic gates, combinational and sequential circuits, and CPU architecture. These topics are crucial for computer knowledge sections in technical exams. Test your digital electronics basics here.
Logic gates and circuitsCombinational vs sequential circuitsMicroprocessor instructionsTruth tables and boolean functions
Digital Logic and Microprocessors Questions
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minimize the number of flip flop in a digital circuit
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minimize the number of gates only in digital circuit
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minimize the number of gates and fan in of a digital circuit
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design gates
C
Correct answer
Explanation
Karnaugh maps are a graphical method for simplifying Boolean expressions. They help minimize both the number of gates and the fan-in (inputs per gate) in digital circuits. Option A is incorrect because K-maps aren't specific to flip-flops. Option B is incomplete because K-maps optimize more than just gate count.
B
Correct answer
Explanation
Combinational circuits have no memory - their output depends only on the current input values. Sequential circuits, which contain memory elements like flip-flops, can store state information. This is a fundamental distinction in digital circuit design.
B
Correct answer
Explanation
Combinational circuits have NO memory elements - outputs depend only on present inputs. Sequential circuits DO have memory (flip-flops, registers) to store state information. The statement claims combinational circuits have memory, which is false.
A,C,D
Correct answer
Explanation
The ^ (XOR), & (AND), and | (OR) operators can be used both as integer bitwise operators (operating on individual bits) and boolean logical operators (operating on boolean values). The ! operator is only a boolean logical operator (logical NOT) and has no integer bitwise counterpart.
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Branch on One
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Branch on Overflow
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Branch on OK
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None of These
B
Correct answer
Explanation
In IBM mainframe assembly, BO (Branch on Overflow) is a conditional branch instruction that transfers control when the overflow condition code is set. This occurs after arithmetic operations that exceed the register capacity. Option A (Branch on One) would likely be a different instruction; Option C is not a standard conditional branch.
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Branch Instruction
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Arithmetic Instruction
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Decimal Instruction
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Assembler Directive
C
Correct answer
Explanation
ZAP (Zero and Add) is a decimal instruction in IBM mainframe assembly that performs decimal arithmetic by converting packed decimal format. It's not a branch instruction (A), general arithmetic instruction (B uses binary arithmetic), or assembler directive (D which provides metadata to assembler). Decimal instructions specifically work with packed decimal data formats.
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Register Operands
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Storage Operands
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Implied Operands
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Immediate Operands
B
Correct answer
Explanation
In IBM z/Architecture (Mainframe) assembly, decimal instructions (such as AP, SP, ZAP) operate on Packed Decimal data. These instructions are 'SS' (Storage-to-Storage) format, meaning both operands reside in memory (storage) rather than registers. This allows for processing large numbers that exceed register sizes.
B
Correct answer
Explanation
AES does NOT use P-Box and D-Box. AES (Rijndael) uses SubBytes (S-Box), ShiftRows (permutation), MixColumns (diffusion), and AddRoundKey (key addition). The 'P-Box, D-Box' terminology belongs to other algorithms, not AES. Also, AES has multiple transformation types, not just three.
B
Correct answer
Explanation
The Sort component in Ab Initio has exactly 2 ports - one input port for receiving unsorted data and one output port for delivering sorted data. This N=2 configuration is fundamental to its single-input single-output design.
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Programmable Logic Array
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Program Logic Array
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Programming Logic Array
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Programmable Logical Array
A
Correct answer
Explanation
PLA stands for Programmable Logic Array, a digital logic device that can be programmed to implement specific combinational logic functions. Option B is incorrect (Program instead of Programmable), Option C uses wrong word form (Programming), and Option D is incorrect (Logical instead of Logic).
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Multi-Dimenssion Metal-Oxide Semiconductor
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Multi-Drain Metal-Oxide Semiconductor
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Multi-Drain Metal-Oxide Spectrometer
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Multi-Diagonal Metal-Oxide Spectrometer
B
Correct answer
Explanation
MD-MOS stands for Multi-Drain Metal-Oxide Semiconductor, which refers to MOSFET devices with multiple drain terminals. These devices are used in analog applications where multiple output currents or signal routing from a single gate input is required.
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Lenz Lnz Control
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Logical Link Control
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Lei Lab Copyright
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Logic Level Converter
B
Correct answer
Explanation
LLC stands for Logical Link Control, one of the two sublayers of the Data Link Layer in the OSI model. It provides flow control and error management over the physical medium, and works with the MAC sublayer to form the complete Data Link Layer.
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Binary Arithmetic
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Decimal Arithmetic
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Floating point arithmetic
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None of the Above
A,B,C
Correct answer
Explanation
IBM Assembler supports binary (fixed-point), decimal (packed or zoned), and floating-point arithmetic instructions to handle different types of numeric data. Since these three options cover the valid arithmetic modes, 'None of the Above' is incorrect.
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AND , OR
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NAND, NOR
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NAND, EX-OR
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EX-OR, EX-NOR
B
Correct answer
Explanation
NAND and NOR gates do not satisfy the associative law: (A NAND B) NAND C ≠ A NAND (B NAND C). In contrast, AND and OR gates are associative. This property makes NAND and NOR fundamentally different in circuit design.