GPIB bus width: Determine the number of dedicated data lines carried by the IEEE-488 (GPIB) bus for parallel data transfer.
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A1
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B4
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C8
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D16
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E9
Answer
Correct Answer: 8
Explanation
Introduction / Context:The IEEE-488 General Purpose Interface Bus (GPIB) is a parallel instrument bus widely used in test and measurement. Understanding its signal lines is foundational for system integration.
Given Data / Assumptions:
- GPIB provides distinct groups of lines: data lines, handshake lines, management/control lines, and ground/returns.
- Only the number of data lines is asked, not the total wire count.
- Data lines are used to carry a byte at a time in parallel.
Concept / Approach:GPIB moves data in 8-bit bytes over dedicated parallel conductors. Separate handshake lines (DAV, NRFD, NDAC) coordinate transfer timing, allowing heterogeneous device speeds.
Step-by-Step Solution:Identify the data group: DIO1 through DIO8.Recognize that handshake and management lines are separate and not counted as data lines.Conclude that there are 8 data lines.
Verification / Alternative check:Pinout references label the parallel data lines as DIO1–DIO8, confirming an 8-bit data path.
Why Other Options Are Wrong:1 or 4 would indicate serial or nibble-width, which GPIB is not. 16 would imply a wider bus than the standard defines for data. 9 is incorrect; the ninth relevant signals are handshake/control, not data.
Common Pitfalls:Confusing total conductor count (including control/handshake/grounds) with the data path width.
Final Answer:8