MAX7000S tri-state control options For Altera (Intel) MAX7000S family CPLDs, how is a tri-state output buffer typically controlled?

Introduction / Context:
CPLD families like MAX7000S allow flexible output enable (OE) control for each I/O macrocell. Designers may need constant drive, globally gated outputs for bus sharing, or context-sensitive enables derived from logic in other macrocells. Recognizing all supported control modes is essential when planning board-level bus architectures.

Given Data / Assumptions:

• Each macrocell output buffer includes an OE control path.
• Global OE pins can gate many outputs simultaneously.
• OE can also be driven by internal logic equations from other macrocells.
• Static configuration can permanently enable or disable a buffer in some modes.

Concept / Approach:

MAX-class CPLDs expose several OE sources: fixed (always on/off), global OE signals, or a product-term/logic-driven OE. This mix supports simple point-to-point signals, multiplexed buses, and time-shared resources using deterministic, low-skew control.

Step-by-Step Solution:

Verification / Alternative check:

Device handbooks show OE selection multiplexers with choices including global signals and product-term-based enables; some fitter options permit fixed enable states.

Why Other Options Are Wrong:

Each single choice describes only one valid mode; the family supports all of them.

Common Pitfalls:

Forgetting active-low vs active-high OE polarity; overlooking bus-hold and slew-rate settings that also affect system behavior.

Final Answer:

All of the above