Difficulty: Easy
Correct Answer: D flip-flop
Explanation:
Introduction / Context:
OLMCs (Output Logic Macrocells) provide per-pin configurability, including choices for combinational vs registered outputs, polarity inversion, tri-state control, and feedback. Understanding the internal multiplexers clarifies signal flow from the product-term matrix to the pin and back into the device for further logic.
Given Data / Assumptions:
Concept / Approach:
The FMUX (feedback/data multiplexer) chooses the signal that feeds the D input of the macrocell's flip-flop. In contrast, the OMUX (output multiplexer) selects whether the pin sees the registered output or a direct combinational product-term sum. Recognizing these roles avoids confusion when reading configuration diagrams.
Step-by-Step Solution:
Verification / Alternative check:
Consult common OLMC block drawings: the data path shows product terms entering an FMUX, then the DFF, then through OMUX to the I/O pin, with optional feedback paths into the matrix.
Why Other Options Are Wrong:
OMUX is post-register; it does not receive FMUX output directly.
“Matrix” refers to the AND/OR array; FMUX does not feed back into the matrix directly.
“PAL” is the device class, not an internal element.
Common Pitfalls:
Mixing up FMUX vs OMUX roles; assuming feedback always bypasses the register. Config bits determine registered or combinational operation and feedback source.
Final Answer:
D flip-flop
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