The objective of the HOPE project is to propose a relevant solution for designing power efficient system on chip devices early in the design flow. On top of classical design flows, this high level approach relies on existing standards. Considering the large number of constraints, especially for performance and energy, designing battery-powered communicating mobile objects in an industrial context is a tough task. With the increasing number of embedded processing units (having high frequencies), the growing size of LCD touch screens or the different available sensors (i.e. camera) or radio interfaces, the energy consumption can rapidly exceeds a threshold unacceptable in regards to the capacity of embedded battery. Therefore, defining a hardware/software architecture that respects the required performance from the system application point of view and owns efficient power management strategies is a highly complex issue. This complexity has two main sources. The first main source of complexity is related to the intrinsic complexity of the communicating object itself. As an example, the Texas Instruments OMAP4 platform includes more than 300 IP blocks that need to be controlled (especially in energy), while the platform has to support the execution of an increasing number of applicative scenarios. For each scenario, a subset of components required for executing the scenario must be identified, as well as a power management strategy (e.g. V, F) for these components. Let us imagine that 50% of the processing power of a component is required for running a scenario. Should the clock frequency be decreased by 50%, or should the component be in idle/sleep mode for half the time? Note that thermal aspects as well as leakage currents must also be considered. For obvious cost reasons, it is moreover not possible to individually control each component (in V and F). So, an optimized partitioning of the system is required. The second main source of complexity is related the inefficiency of existing system level design tools to cope this complex issue. The identified solution must be consistent to support both the execution of applicative scenarios with their corresponding dynamism (including the embedded software) and a power management strategy. Verifying this consistency for the required level of performance is also a complex task. Finally, it is well known that the quality of the embedded software also has a non negligible impact on energy and temperature. So, being able to evaluate the efficiency of the software and identify optimization opportunities are key functionalities from a designer point of view. At micro architecture level, industrials have technologies and mature tools to model an architecture integrating common techniques used for power optimizations (e.g. power gating). The UPF (Unified Power Format - IEEE 1801) standard for instance defines primitives allowing designers to add power gating features on top of a functional RTL model. While essential at RTL level, this type of standard is not designed for a use at system level, so early in the design flow. The HOPE project intends to study and develop an approach for helping system level design and is based on the following main items: • An approach for sizing power architecture from a functional behavior analysis: break down the architecture in domains and define a power strategy (i.e. power intent); evaluate the solution in terms of power and temperature. • Study and develop SystemC-TLM models of components controlling power, clock and reset. Add power intent to purely functional SystemC-TLM models of a virtual platform. Verify functional/non-functional consistency and accurately evaluate the dynamic variation of the power consumption and the temperature. • Connect the developed models to an existing design flow with constraints vs. requirements tracking.

The new 2013/35 EU Directive, defining minimum health and safety requirements regarding the exposure of workers to electromagnetics fields, shall be transposed in member states regulations by July 2016. These exposure limits for workers are expressed in terms of internal electric field and Specific Absorption Rate (SAR). Similar exposure limits (head and trunk current densities and SAR) have already been applied in the French Ministry of Defence since 2003. Indeed, soldiers also evolve next to high power emitters which can radiate fields above accepted reference levels over large areas. A trade-off between jamming efficiency or communication distance (in HF, VHF or UHF) and conformity with respect to regulation on personnel exposure is therefore sought. As it is difficult to measure the EM quantities inside the human body, the demonstration of conformity versus regulation usually relies on numerical simulation (dosimetry) taking into account complex human models as well as surrounding emitters and structures. These numerical tools solving Maxwell’s equations must be adapted in order to meet the new challenges brought by civil and military regulations (exposure limits expressed in terms of SAR, current densities or internal electric fields). Tools able to handle such complex models rely on few numerical methods: the Finite Element Method (FEM), the Finite Difference Time Domain (FDTD) method, the resolution of integral equations with the Method of Moment (MoM), the Transmission-Line Matrix (TLM) method, and the recent Galerkin Discontinuous Time Domain (GDTD) method. Each of these can be the most suitable method to use depending on the case. For numerical dosimetry, volumic methods are preferred as human models are usually described in terms of volumic pixels (voxels) with similar size as the computation cell. If transients are to be included, then both FDTD and TLM prevail. The first one is the more popular because of its simple algorithm, and has been implemented into several commercial tools. Although published a decade later, TLM has not been as widely used. It is however proved to be less dispersive, more physical because of its analogy with circuit models, and inherently stable while using the maximum allowed time step for stability. Moreover, recent works showed that TLM provides faster convergence and is more accurate than FDTD (or FIT) for structures with highly contrasted constitutive parameters such as voxel human heterogeneous models. However, only one commercial tool (developed by a foreign company) is currently based on TLM, with little past and foreseen evolution, as FDTD prevails among electromagnetic simulation users. The objective of the present project is to elaborate the bricks of a versatile TLM simulator oriented towards military and civil dosimetry needs with extensions such as thermal coupling (strong hybridization) not available in commercial tools. It will rely on the recognized competence of 2 French laboratories working on TLM along with the competence of DGA Aeronautical Systems for Defence applications, and will be based on existing modules developed in these laboratories. Thermal effects of electromagnetic waves will also be studied through a novel TLM thermal model. Significant outcome is foreseen. First, the competence of the French TLM community will be sustained and reinforced. Second, the project will deliver a novel TLM simulator with open computation core and massively paralleled features, of significant use for Defence and for industrial applications. Finally, the structure of this demonstrator will enable constant evolution and diffusion towards telecommunications, biomedical applications, as well as RF drying (wood, vegetables, …) and RF cooking.