If only I could organize my thoughts as easily as Silicon Storage Technology's All-in-OneMemory organizes its code and data. This device combines the benefits of NOR and NAND flash, RAM, and built-in controllers, so all your memory needs can coexist under one roof (see the figure, part A). This provides an ideal execute-in-place (XIP) environment in which program code executes in the same place in which it is stored.
SST relied on fancy system-in-package (SiP) footwork to create this device, which targets embedded devices such as cell phones, portable media players, personal navigation devices, medical instruments, and set-top boxes. With multiple gigabytes of XIP storage, the All-in-OneMemory suits the growing needs of multimedia-based devices as more and more devices offer high-resolution digital video.
The All-in-OneMemory's host-configurable (except the NOR) memory map is accessible via the host bus (see the figure, part B). The NOR memory holds boot code for instant and secure boot. The pseudo-NOR is available for code execution and data storage. A RAM block can be used for temporary data and caching. And, there's a sequential access block for non-XIP code and data storage.
While all of this is contained in one small-footprint package, the device's built-in 32-bit microcontroller decides the best memory for each task and communicates that decision to an external host CPU. The controller also provides memory demand paging, flash memory management, and a standard ATA data storage protocol. This simplifies the host interface and reduces design and test times, as well as the overall system cost.
"I am impressed with the approach SST has taken with its All-in-OneMemory technology," says Mark DeVoss, a senior analyst at iSuppli Corp. "Overall it seems like a well-thought-out scheme for rearchitecting the memory subsystem to address the cost and time-to-market needs of system designers working on mobile and consumer electronics. SST has taken the complexity out of hybrid memory architectures by enabling a single-bus memory subsystem that uses the standard SRAM host interface, which is a huge benefit for designers."
Contact the company for information about block sizes and pricing. The All-inOneMemory will be available in the second half of this year. For more about system memory and the tradeoffs of each memory type, see "So, What Was That Memory Technology Again?".
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