MSI Logic Circuits Questions

• Function of a demultiplexer – does a demultiplexer convert a binary or other code into a recognizable number or character for display, or is that the role of a decoder/driver?
• Demultiplexer behavior – does a demultiplexer take a single input signal and “turn it into a binary number,” or does it distribute that signal to one of many outputs based on select lines?
• BCD-to-7-segment 7447 outputs – if segment outputs a, b, c, d, and g are asserted (active), which digit appears on the display, and is it 5 as claimed?
• Hardware description languages – does AHDL (Altera Hardware Description Language) lack a multiplication operator, or does it support “*” for arithmetic in synthesizable expressions?
• Definition check – is a multiplexer (MUX) the device that converts a code into a recognizable number or character for display, or is that the specific function of a decoder/driver?
• MSI logic concept — multiplexer behavior: In medium-scale integration (MSI) digital design, a multiplexer (MUX) is a data selector that routes exactly one of several input lines to a single output line under the control of select signals. Evaluate the statement: “A device that selects one of several inputs to be placed on the output is a multiplexer.”
• Computer engineering terminology — meaning of a “variable”: In algorithm design and hardware description, a VARIABLE can be viewed as a named storage placeholder used to record numeric values (or symbols) for later use in expressions, decisions, or assignments. Assess the analogy: “A variable is like a piece of scrap paper used to write down some numbers that can be used later.”
• Identify the MSI function — decoder vs comparator: A circuit that translates an n-bit binary code word into exactly one active output line (one-hot) corresponding to its numeric value is called a ________. The statement labels it a “comparator”; evaluate this claim and choose the correct classification.
• Equality testing in MSI — definition of a comparator: A logic circuit that determines whether one binary input is equal to another (optionally also indicating greater-than or less-than) is called a comparator. Judge the correctness of this definition.
• Terminology — multiplexer select inputs: In data selectors, the select inputs are often referred to as address lines because they choose which input line is routed to the output. Evaluate the statement.
• Decoder behavior — number of active outputs: For standard binary-to-one-of-N decoders, only one output line should be active for any valid input code (one-hot). Assess the claim: “It is normal for more than one decoder output to be active at the same time.”
• HDL fundamentals — meaning of a “process”: In hardware description languages (e.g., VHDL, SystemVerilog), a process (or always block) models behavior that executes on events or clock edges, not a mere physical wire. Evaluate the statement: “In HDL, a process is usually thought of as a wire connecting two points in a circuit.”
• Priority encoder truth — 74148 I1 active case: For the 74148 8-to-3 priority encoder (active-low inputs and active-low outputs), when data input I1 is the only active input (asserted), what is the output code? The statement claims A0 = 0, A1 = 0, A2 = 1; evaluate its correctness.
• Does a multiplexer “serialize” data by definition? A multiplexer provides one-of-N selection at its output. Consider the statement: “Basically, a multiplexer changes parallel data inputs to a serial output.” Decide if this characterization is accurate in general.
• Using a 7485 four-bit magnitude comparator — specific case check: Given A = 0110 (decimal 6) and B = 1010 (decimal 10), evaluate the following claimed outputs for the 7485 comparator: A < B = 1, A = B = 0, A > B = 1. Determine whether this set is valid.
• Computer organization — Evaluate the statement: “Modern computers transfer data between different devices over a common set of connecting lines called a data bus.”
• VHDL semantics — Evaluate the statement: “A very important attribute of the conditional signal assignment statement is its sequential operation.”
• 74×151 8-to-1 multiplexer — To select data input I3, what binary levels must be applied to the select inputs (S2, S1, S0)?
• 74LS138 decoder — Evaluate: “Output 6 is selected when A0 = 1, A1 = 1, A2 = 0 (with the device enabled).”
• Comparator definition — Evaluate: “A device that determines which of two numbers is greater is a comparator.”