High Level Synthesis (HLS) tool does not only simplify the designing operation and rapid prototyping but also allows the designers to explore large number of design’s techniques such as parallelism, pipeline, memory partitioning and many other techniques. Turbo decoder based on Maximum APosterior Probability (MAP) algorithm is designed in this work using Vivado HLS. The normal turbo decoder with two MAP decoders were implemented with and without parallelism and proposed a new design of turbo decoder with one MAP decoder and it was designed with and without parallelism using different window technique in HLS tool which it is not explored previously. These designs were implemented for different frame size in this work. A comp-arison in latency and resource utilization where done and how a tradeoff done between these two parameters to reach the specific design that we need. The new design produces better results.