Serial quad I/O (SQI) flash memory
SST (Silicon Storage Technology, Inc.), a leader in flash memory technology, announced the new 26 Series Serial Quad I/O (SQI) family of 4-bit multiplexed I/O serial interface flash memory devices. The Serial Quad I/O™ (SQI™) family of 4-bit, multiplexed I/O, serial-interface, flash-memory devices features a sixwire, 4-bit I/O interface that allows for low-power, high-performance operation in a low pin-count package, occupying less board space and ultimately lowering total system costs. SST 26 Series boosts performance while maintaining the compact form factor of standard serial devices. Utilizing Serial Quad Interface (SQI) and operating at frequencies reaching 80 MHz, SST 26 Series is a perfect choice for Bluetooth headsets, optical disk drives and GPS applications.
SST 26 Series SQI flash memories are manufactured with SST’s proprietary, high performance CMOS SuperFlash® Technology, significantly improving performance and reliability while lowering power consumption. For cutting edge designs requiring high bandwidth and compact layout, SST 26 Series is an ideal solution. The 26 Series’ low pin count and enhanced serial interface architecture make the family an ideal code storage solution for applications such as ultra low-cost handsets, Bluetooth headsets, optical disk drives and GPS devices, where small form factor, low power consumption and high data rate are a must. With a fast 80 MHz operating frequency and a specialized instruction set, SST’s 26 Series SQI flash devices target execute-in-place (XIP) applications, allowing programs to be stored and executed directly from the flash memory without the need for code shadowing on an SRAM, thus further increasing overall system performance. All members of the 26 Series, SQI family are manufactured with SST proprietary, high-performance CMOS SuperFlash® technology. The split-gate cell design and thick-oxide tunneling injector attain better reliability and manufacturability compared with alternate approaches.
The 26 Series SQI devices feature a 4-bit multiplexed serial interface architecture and up to a 350 Mbit/sec. sustained burst data rate that provides performance exceeding typical parallel flash memory. To provide additional system speed and performance, the 26 Series supports 8-, 16-, 32- and 64-Byte burst mode operation with wrap around, which reduces the memory’s read access time, as well as memory index jumping, which reduces the number of input clock cycles. All products in the 26 Series family use a small-outline, 8-pin package to provide a comparable design footprint. The 26 Series SQI devices offer superior reliability of 100,000 cycles endurance (typical) and greater than 100 years data retention. The active read current of the devices is only 15 mA (typical at 80 MHz) and standby current is a mere 10 µA (typical). All 26 Series SQI devices are available in both commercial and industrial temperature ranges, and are offered in an 8-contact WSON (6 mm x 5 mm) or 8-lead SOIC (200 mil) package.
Designers are always looking to maximize performance and reduce the overall footprint and power consumption of their embedded designs, particularly in portable applications. The innovative features and new operating modes we developed allow our 26 Series SQI memory devices to eclipse the performance capabilities of other 4-bit multiplexed I/O serial interface flash memory products in the market today without sacrificing low power consumption or small form factor. The 26 Series SQI devices offer memory write performance enhancements to improve overall device performance, including flexible erase capability to erase small block sectors on the chip in as little as 25 ms or the entire flash memory chip in 50 ms. The devices also support write suspend and resume operation so a program can suspend a write operation to access another block of memory within the same clock cycle.
Code security was also improved in the development of SST’s 26 Series SQI flash memory. All devices in the family support software write protection for individual blocks, the upper and lower 64-KBytes of memory are partitioned into smaller 8-KByte sectors that can both read- and write-lock. In addition, the devices include a one-time programmable secure ID area, consisting of a 64-bit factory programmed unique ID and a 192-bit user programmable block.
