Inside an OLMC — FMUX destination Within an Output Logic Macrocell (OLMC) of a PAL/GAL-class device, the FMUX (feedback/data multiplexer) signal is routed to which internal element?

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:

• The FMUX selects among product-term sources or feedback options used to drive the storage element's data input.
• OLMCs typically include a D-type flip-flop that can be inserted or bypassed.
• An OMUX usually selects what ultimately drives the pin (registered vs combinational path).

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