JMicron JMF612

The JMicron JMF612 is a SATA II SSD controller released in 2009, unusual for combining an SSD controller and a USB 2.0 bridge in a single chip, an unusual combination that allows a drive to present itself over either SATA or USB without a secondary bridge IC. The chip is housed in a 281-ball TFBGA package.

Internally, the JMF612 uses a 32-bit embedded processor and supports up to 8 NAND flash channels (configurable down to 2), with up to 16 chip-enables per channel. External DDR or DDR2 SDRAM is required, in densities from 128 Mb to 2 Gb. Error correction is handled by a BCH engine supporting 16-bit or 24-bit correction per 512-byte sector. The controller supports 5x, 4x, and 3x nm process NAND in both MLC and SLC configurations, with dynamic and static wear-leveling.

The JMF612 was used in the Western Digital SiliconEdge Blue, one of WD's earliest SSD offerings. Performance was limited by the SATA II interface ceiling and the controller's architecture, placing it behind contemporaries using Indilinx or SandForce silicon.