FusionHD: Intelligent Flash Memory for Next‑Gen IoT

While most 8‑bit flash memory chips are ubiquitous in IoT, IIoT, smart metering, home automation, consumer electronics, and medical monitoring, they’re typically limited by simple, power‑hungry programming cycles. Adesto Technologies’ FusionHD series tackles this head‑on with a suite of smart features that elevate ultra‑low‑power memory to a new level.

Streamlined Programming
Traditional 8‑bit flash devices are arranged in 4‑kb blocks. Updating even a few bytes requires reading the entire block into a cache, erasing it, and re‑programming the whole block—an operation that consumes time and forces the CPU to stay awake, polling the device for completion.

FusionHD eliminates that overhead. The chip can erase or program a 128‑bit page—or the entire 4‑kb block—directly, saving both time and power for small data packets. A dedicated read‑modify‑write command lets the flash handle up to 128 bits of data autonomously, requiring no CPU intervention.

Even more clever is the way FusionHD redefines the SPI interface. After the CPU issues a write command, one of the SPI pins switches to an edge‑triggered interrupt mode. The CPU can then perform other tasks or sleep, and the chip will signal completion via the interrupt—freeing valuable processor cycles.

Flexible SRAM Buffer
All flash memories include an internal SRAM buffer that decouples internal and external speeds. However, each erase or program cycle gradually wears out cells; after roughly 100,000 cycles a cell may fail. FusionHD’s flexible SRAM buffer allows data to be written without immediately triggering a program cycle, giving the CPU control over when a write occurs and extending the device’s lifespan.

By combining automatic, low‑power programming with intelligent interrupt handling and a flexible buffer, FusionHD delivers a smarter, more reliable memory solution for the next wave of connected products.