FLARE: A design environment for FLASH-based space applications

Designing a mass-memory device (i.e., a solid-state recorder) is one of the typical issues of mission-critical space system applications. Flash-memories could be used for this goal: a huge number of parameters and trade-offs need to be explored. Flash-memories are nonvolatile, shock-resistant and power-economic, but in turn have different drawback: e.g., their cost is higher than normal hard disk and the number of erasure cycles is bounded. Moreover space environment presents various issues especially because of radiations: different and quite often contrasting dimensions need to be explored during the design of a flash-memory based solid-state recorder. No systematic approach has so far been proposed to consider them all as a whole: as a consequence a novel design environment currently under development is aimed at supporting the design of flash-based mass-memory device for space application

Flash-memories in Space Applications: Trends and Challenges

Nowadays space applications are provided with a processing power absolutely overcoming the one available just a few years ago. Typical mission-critical space system applications include also the issue of solid-state recorder(s). Flash-memories are nonvolatile, shock-resistant and power-economic, but in turn have different drawbacks. A solid-state recorder for space applications should satisfy many different constraints especially because of the issues related to radiations: proper countermeasures are needed, together with EDAC and testing techniques in order to improve the dependability of the whole system. Different and quite often contrasting dimensions need to be explored during the design of a flash-memory based solid- state recorder. In particular, we shall explore the most important flash-memory design dimensions and trade-offs to tackle during the design of flash-based hard disks for space application

Optimizing the flash-RAM energy trade-off in deeply embedded systems

Deeply embedded systems often have the tightest constraints on energy consumption, requiring that they consume tiny amounts of current and run on batteries for years. However, they typically execute code directly from flash, instead of the more energy efficient RAM. We implement a novel compiler optimization that exploits the relative efficiency of RAM by statically moving carefully selected basic blocks from flash to RAM. Our technique uses integer linear programming, with an energy cost model to select a good set of basic blocks to place into RAM, without impacting stack or data storage. We evaluate our optimization on a common ARM microcontroller and succeed in reducing the average power consumption by up to 41% and reducing energy consumption by up to 22%, while increasing execution time. A case study is presented, where an application executes code then sleeps for a period of time. For this example we show that our optimization could allow the application to run on battery for up to 32% longer. We also show that for this scenario the total application energy can be reduced, even if the optimization increases the execution time of the code

Exploring Design Dimensions in Flash-based Mass-memory Devices

Mission-critical space system applications present several issues: a typical one is the design of a mass-memory device (i.e., a solid- state recorder). This goal could be accomplished by using flash- memories: the exploration of a huge number of parameters and trade-offs is needed. On the one hand flash-memories are nonvolatile, shock-resistant and power-economic, but on the other hand their cost is higher than normal hard disk, the number of erasure cycles is bounded and other different drawbacks have to be considered. In addition space environment presents various issues especially because of radiations: the design of a flash- memory based solid-state recorder implies the exploration of different and quite often contrasting dimensions. No systematic approach has so far been proposed to consider them all as a whole: as a consequence the design of flash-based mass-memory device for space applications is intended to be supported by a novel design environment currently under development and refinemen