Select the statement that best describes a fusible-link PROM (Programmable Read-Only Memory).

Introduction / Context:
A fusible-link PROM is a classic nonvolatile memory in which stored bits are created by selectively blowing microscopic fuses. Understanding the programmability and permanence of this technology is important for legacy systems and fundamentals.

Given Data / Assumptions:

• Programming is performed by the end user using a programmer device.
• Once a fuse is blown, the change is permanent.
• No built-in erase mechanism exists for fusible-link PROMs.

Concept / Approach:
Fusible-link PROMs start with all links intact and represent one logical state. Programming selectively opens links by a controlled current pulse, changing those cells to the opposite state. Because there is no way to restore a blown fuse, these devices are one-time programmable at the user level.

Step-by-Step Solution:
Identify technology mechanism: physical fuse links.Determine programmability: performed by user with a PROM programmer.Assess reversibility: irreversible, hence one-time programmable.Select the description that matches these facts.

Verification / Alternative check:
Device datasheets and textbooks explicitly call fusible-link PROMs OTP (one-time programmable) memories programmed by the user after manufacturing.

Why Other Options Are Wrong:
Manufacturer-programmable: confusion with mask ROM, which is programmed during fabrication.Reprogrammable options: describe EPROM/EEPROM/Flash, not fusible-link PROM.UV erasable: that is EPROM with a quartz window, not fusible-link PROM.

Common Pitfalls:
Mixing up PROM with EPROM or mask ROM. PROM is user-programmable but not erasable; mask ROM is factory programmed; EPROM is UV erasable; EEPROM/Flash are electrically erasable.

Final Answer:
User-programmable, one-time programmable