GAL16V8 feedback selection path In the GAL16V8 output macrocell, which internal multiplexer selects the signal that is fed back into the device’s input matrix for further logic use?

Introduction / Context:
Many simple PLDs allow the output of a macrocell to be “fed back” into the input matrix so that the signal can participate in other equations, enabling state machines and wider logic functions. In the GAL16V8, this routing is made selectable inside each macrocell.

Given Data / Assumptions:

• GAL16V8 macrocells include OMUX (output datapath), TSMUX (tri-state enable selection), PTMUX (product-term choice), and FMUX (feedback source selection).
• “Feedback into the input matrix” means taking a macrocell result and returning it as an input to the shared AND array.
• The macrocell can often choose between the registered output, the combinational node, or a polarity-controlled version for feedback.

Concept / Approach:
The FMUX—Feedback Multiplexer—controls which internal node is presented to the input matrix as a feedback signal. This provides flexibility to use registered or combinational versions of the macrocell output without consuming extra pins.

Step-by-Step Solution:

Verification / Alternative check:
Reference a GAL16V8 block diagram: the feedback node typically branches from the macrocell and passes through an FMUX to the input array.

Why Other Options Are Wrong:
OMUX routes the functional output to the pin or register path. TSMUX controls whether the output is enabled (OE). PTMUX deals with product-term selection, not feedback.

Common Pitfalls:
Confusing the “output path to pin” (OMUX) with “feedback path to matrix” (FMUX). They serve different routing purposes.

Final Answer:
FMUX