Multi-core processors are being widely used in safety-critical systems.Unfortunately, the introduction of performance-enhancing architectural elements, such as pipelines, out-of-order execution, dynamic branch prediction, caches and inter-cores resource-sharing, make WCET(worst-case execution time) analysis of a system become more difficult.Thus, time-predictable system design is established to meet the challenge of building systems for which WCET can be statically and easily analyzed.At the software level, this paper proposes a time-predictable multi-threaded code generation based on synchronous-model development.At the platform level, it presents a time-predictable multi-core architecture model in AADL(architecture analysis and design language), and then maps the multi-threaded code to this model.Real-time specifications propagate down in the system hierarchy.As a result, the proposed method integrates time predictability across several design layers, and finally reduces the complexity of WCET analysis.