Bitstream Compaction iCE40 - Bitstreams and Reconfiguration Time Measurements

The HDF5 file contains data from an experiment concerning bitstream compaction for Lattice iCE40 FPGAs. Four projects were synthesized with two different toolchains and afterwards compacted in two different levels, resulting in 24 bitstreams. The creation of each bitstream was repeated 100 times to guard against variations caused by errors in the toolchains or by the compaction. No such errors occured and the configuration is the same for every repetition. The reconfiguration time for each of the 24 bitstreams was measured 10.000 times. Toolchains: Lattice iCEcube2 Open Source Toolchain (Yosys, nextpnr, Project Icestorm) Projects: empty: Completely empty project, that uses no FPGA resources. b12: A project from the ITC’99 benchmark suite. aes: A simple AES-128 encryption module. picosoc: RISC-V system on a chip Compaction levels: original: uncompacted bitstream builtin: compacted with two methods also available in iCEcube2 compact: compacted with all five methods File structure: The data is organzied hierarchical. It is first split between bitstreams and measurements, then by toolchain, then by project and finally by compaction level.本HDF5文件包含一项针对莱迪思iCE40现场可编程门阵列（Field-Programmable Gate Array，FPGA）比特流（bitstream）压缩的实验数据。研究团队采用两种不同的工具链对4个测试项目进行逻辑综合，随后以三种不同的压缩规格对生成的综合结果进行压缩处理，最终得到24组比特流。 为规避工具链误差或压缩过程引入的变量干扰，每组比特流的生成流程均重复执行100次。本次实验未出现此类误差，且所有重复批次的配置均保持一致。针对24组比特流各自的重配置时间，均开展了10000次测量。 工具链：共两类，分别为莱迪思iCEcube2专有工具链，以及由Yosys、nextpnr与Project Icestorm组成的开源工具链。 测试项目：共4个，具体如下： - empty：无任何FPGA资源占用的纯空项目； - b12：源自ITC’99基准测试套件的项目； - aes：简易AES-128加密模块； - picosoc：基于RISC-V架构的片上系统（System on Chip，SoC）。 压缩等级：共三类，具体如下： - original：未经过压缩的原生比特流； - builtin：采用iCEcube2内置的两种压缩方法完成压缩的比特流； - compact：采用全部五种压缩方法完成压缩的比特流。 文件结构：本数据集采用层级化组织形式，首先按比特流与测量数据进行一级划分，随后依次按工具链、测试项目以及压缩等级进行细分。