Nonvolatile memory technologies: Which memory type is nonvolatile and supports erase/program operations in blocks or sectors (rather than erasing one byte at a time)?

Introduction / Context:
Modern embedded systems rely on nonvolatile memories to retain code and data without power. Different technologies vary in how they are written and erased. This question distinguishes sector/block-erasable flash from byte-erasable EEPROM and UV-erasable EPROM.

Given Data / Assumptions:

• Nonvolatile storage is required (data retained without power).
• Erase granularity is at the sector/block level, not per byte.
• Common memory families considered: flash, EPROM, EEPROM, mask-programmed ROM (MPROM).

Concept / Approach:
Flash memory stores charge on floating gates and is electrically erasable, but the erase operation occurs over a block/sector. EEPROM also uses floating gates but typically supports byte-level erase/write. EPROM requires ultraviolet light to erase the entire chip. MPROM is programmed by mask at fabrication and cannot be altered after manufacture.

Step-by-Step Solution:
Identify the erase granularity requirement: sector/block-level erase.Match to technology: flash supports block/sector erase.Eliminate alternatives: EEPROM is byte-erasable; EPROM needs UV-light chip erase; MPROM is fixed at fabrication.Conclude: flash memory is correct.

Verification / Alternative check:
Datasheets for NOR/NAND flash specify erase block sizes (e.g., 4 KB, 64 KB, or larger), confirming sector-based erase and page-based programming.

Why Other Options Are Wrong:
EPROM: ultraviolet whole-chip erase, not sector electrical erase.EEPROM: typically byte or small-page erase/write, not large sectors.MPROM: not erasable or reprogrammable after production.

Common Pitfalls:
Assuming EEPROM and flash behave identically. They share floating-gate physics but differ in architecture, endurance, and erase granularity.

Final Answer:
flash memory