The newest Open NAND Flash Interface (ONFI) 3 standard offers many benefits for high-performance NAND Flash applications. This article describes many of the improvements from prior ONFI releases, and outlines the design requirements necessary to obtain the higher performance capabilities. ONFI 3 offers these key improvements for systems design:

  • Performance of 400M transfers/s (transfers/s)
  • On-die termination (ODT)
  • Reduced signal level (1.8 V)

At 400M transfers/s, ONFI 3 runs at twice the performance of the previous ONFI 2 specification. ONFI 3 also offers useful features such as on-die termination, reduced signaling voltage, warm-up cycles, and volume addressing. This article reviews the ONFI 3 and related Toggle 2 specifications, and shows how they benefit system and controller designers while providing higher levels of performance and reducing costs.

What market segments will utilize this latest release? One target market is larger array applications due to the increase in the number of parallel Flash channels (a controller is a channel), and the high number of NAND Flash dies. Low-power applications will also be a candidate, due to the lower voltage, on-die termination, and higher performance provided by ONFI 3. A review of how ONFI and NAND have progressed is important to understand why a migration is necessary to continue the growth of NAND in current and new applications.