ECE 260 : Digital Logic Design Question & Answers "6004" is: - ANSWER: the course at MIT that ELEN3431 is modeled after. A 256k -word memory uses 16 -bit words. How many parallel data lines are required to pass the data to the CPU for processing? Do no count clock, sync, or other protocol lines. - ANSWER: 16 A combinational circuit is a zeroth -stage pipeline. - ANSWER: True a combinational device is a circuit element that has: - ANSWER: 1. One or more digital outputs 2. One or more digital inputs 3. A functional specification A disadvantage of a programmable control system is that we cannot reconfigure it to compute new functions. - ANSWER: False A Don't Care is just a ________ and _______ that the _______ does not depend on. - ANSWER: truth table, input, output A finite state machine cannot be thought of as programmable because it has a finite number of states. - ANSWER: False A finite state machine has... - ANSWER: ...STATES, INPUTS, OUTPUTS, Transition Rules and Output Rules. A FSM can add or subtract two arbitrarily large binary numbers. - ANSWER: True A K-Stage pipeline is a cyclic circuit having exactly K registers on every path from an input to an output. - ANSWER: False A lenient combinational device... - ANSWER: ...is where the output is guaranteed to be valid when any combination of inputs sufficient to determine the output value has been valid for at least Tpd. A lenient device... - ANSWER: ...tolerates transitions and invalid levels on irrelevant inputs. A MUX can be used to implement an arbitrary Boolean function. - ANSWER: True A mux can be used to make a latch, which is a... - ANSWER: ...settable storage element. A read -only memory can be used to create a finite state machine along with a register. - ANSWER: True A recursive procedure is one that calls itself. - ANSWER: True A simple controller board has two thousand 8 -bit memory locations and two 8 -bit registers. How many different states can this board be in? - ANSWER: (2)^16,016 A single periodic clock signal shared among all clocked devices is what characterizes the only -
clock synchronous discipline. - ANSWER: False A state transition table is just a Truth Table with state transition information included. - ANSWER: True a system is a structure that is guaranteed to exhibit ________, assuming all of its components obey their specified behaviors. - ANSWER: a specified behavior a zero in front of a number, i.e. 0222, indicates what? - ANSWER: an octal number. Advantages of pipelining? - ANSWER: Allows us to increase throughput by breaking up long combinational paths and thus increasing clock frequency. All Beta machine instructions will fit in what size word? - ANSWER: 32 bit All state transition diagrams can be described by truth tables. - ANSWER: True An FSM can be designed to be a well -formed parentheses checker. - ANSWER: False An N -pipe multiplier takes advantage of structure by just reusing the same combinational block on different data. - ANSWER: False AND, OR, and NOT are sufficient to produce any Boolean expression. - ANSWER: True Assume that "173" is a hexadecimal number. What is it in binary? - ANSWER: 101110011 Assume that "173" is an octal number. What is it in binary? - ANSWER: 1111011 At the bottom of our abstraction hierarchy is [X] and at the top is [Y]. - ANSWER: [CMOS gates] [Registers] Ball-grid arrays are used to allow more efficient pipelining in large scale -multipliers. - ANSWER: False Big idea #3 in Computer Science was... - ANSWER: computability Binary multiplication is just shifting and anding. - ANSWER: False By regrouping partial products we can... - ANSWER: ...reduce the number of additions. Can a combinational device contain directed cycles? - ANSWER: No Church's thesis states that... - ANSWER: ...every discrete function computable by ANY realizable machine is computable by some Turing machine. Compilation happens during execution while interpretation happens after. - ANSWER: False Conditional Delay is a lower bound on time from invalid inputs to invalid outputs. - ANSWER: False, Contamination Delay. convert hexadecimal 101 into octal. - ANSWER: 401 Convert octal "101" into hexadecimal - ANSWER: 41 Could the RoboAnt schematic be redrawn using only NAND gates? - ANSWER: Yes Current flows between the diffusion terminals in a MOSFET if the voltage on the gate terminal is such that it creates a conducting "channel", otherwise the MOSFET is off and the current does not flow between the diffusion terminals. - ANSWER: True Data is popped off the stack in the same order that it is pushed on. - ANSWER: False, in reverse order.
clock synchronous discipline. - ANSWER: False A state transition table is just a Truth Table with state transition information included. - ANSWER: True a system is a structure that is guaranteed to exhibit ________, assuming all of its components obey their specified behaviors. - ANSWER: a specified behavior a zero in front of a number, i.e. 0222, indicates what? - ANSWER: an octal number. Advantages of pipelining? - ANSWER: Allows us to increase throughput by breaking up long combinational paths and thus increasing clock frequency. All Beta machine instructions will fit in what size word? - ANSWER: 32 bit All state transition diagrams can be described by truth tables. - ANSWER: True An FSM can be designed to be a well -formed parentheses checker. - ANSWER: False An N -pipe multiplier takes advantage of structure by just reusing the same combinational block on different data. - ANSWER: False AND, OR, and NOT are sufficient to produce any Boolean expression. - ANSWER: True Assume that "173" is a hexadecimal number. What is it in binary? - ANSWER: 101110011 Assume that "173" is an octal number. What is it in binary? - ANSWER: 1111011 At the bottom of our abstraction hierarchy is [X] and at the top is [Y]. - ANSWER: [CMOS gates] [Registers] Ball-grid arrays are used to allow more efficient pipelining in large scale -multipliers. - ANSWER: False Big idea #3 in Computer Science was... - ANSWER: computability Binary multiplication is just shifting and anding. - ANSWER: False By regrouping partial products we can... - ANSWER: ...reduce the number of additions. Can a combinational device contain directed cycles? - ANSWER: No Church's thesis states that... - ANSWER: ...every discrete function computable by ANY realizable machine is computable by some Turing machine. Compilation happens during execution while interpretation happens after. - ANSWER: False Conditional Delay is a lower bound on time from invalid inputs to invalid outputs. - ANSWER: False, Contamination Delay. convert hexadecimal 101 into octal. - ANSWER: 401 Convert octal "101" into hexadecimal - ANSWER: 41 Could the RoboAnt schematic be redrawn using only NAND gates? - ANSWER: Yes Current flows between the diffusion terminals in a MOSFET if the voltage on the gate terminal is such that it creates a conducting "channel", otherwise the MOSFET is off and the current does not flow between the diffusion terminals. - ANSWER: True Data is popped off the stack in the same order that it is pushed on. - ANSWER: False, in reverse order.
