"""
NAND Flash SSD Simulation (Modular)
-----------------------------------
This file documents the SSD architecture and usage for the modular simulation.

Components:
- nand_cell.py: MultiLevelCell (single cell physics/logic)
- nand_page.py: Page (group of cells, ECC)
- nand_block.py: Block (group of pages)
- nand_plane.py: Plane (group of blocks)
- dram_cache.py: DRAMCache, Buffer (cache, buffer, metadata)
- ftl.py: FTL (Flash Translation Layer, mapping table)
- ssd_controller.py: SSDController (manages all above, FTL, cache, buffer)
- main.py: Demo/entry point

Usage:
------
Import and use the SSDController and other components in your own scripts, or run main.py for a demo.

Example:
    from ssd_controller import SSDController
    ssd = SSDController(...)
    ssd.program(lba, data)
    ssd.read(lba)

See main.py for a full demonstration of SSD features, including DRAM cache, buffer, FTL, wear leveling, garbage collection, and retention simulation.
"""