Introduction / Context:
Generic Array Logic (GAL) devices such as the GAL16V8 organize logic around Output Logic Macrocells (OLMCs). A key feature is a feedback multiplexer (often labeled FMUX) that determines what signal is returned to the AND array (input matrix) for building more complex equations.
Given Data / Assumptions:
- GAL16V8 OLMCs support combinatorial and registered modes.
- Feedback can source from the macrocell output, internal node, or registered output depending on mode.
- The FMUX selects the feedback source that re-enters the input matrix (AND array).
Concept / Approach:
The feedback path enables product terms in one macrocell to reference the result of another, supporting multi-level logic within the constraints of a PLA-like structure. The FMUX is the selector that chooses which internal signal is fed back.
Step-by-Step Solution:
Identify OLMC components: product-term OR, optional register, output buffer, feedback mux.Confirm FMUX role: chooses feedback source (registered or combinatorial).Therefore, the statement matches the architecture → accurate.
Verification / Alternative check:
Consult a GAL16V8 functional block diagram; a selectable feedback path to the AND array is clearly shown.
Why Other Options Are Wrong:
Incorrect: Contradicts documented macrocell behavior.Only true for registered mode: Feedback exists for both modes (source differs).Applies only to active-LOW paths: Polarity control is separate from feedback selection.
Common Pitfalls:
Assuming feedback always equals the pin state; internal selection may differ.Confusing input matrix (AND plane) with external pin routing.
Final Answer:
Correct
Discussion & Comments