The history of System-on-Chip (SoC)

Do we prefer to have a small electronic device or a larger one? The answer will often be “the smaller one”. However, before the commercialization of small radios, many people were interested in having big radios for the extravagance. Subsequently, at the beginning of the emergence of compact radios, those who preferred the flamboyance of large radios refused using compact radios. Slowly, but surely, the overwhelming benefits of owning a more compact radio led to the proliferation of smaller devices. These days the progression of the technology enables cutting-edge companies to encapsulate different parts of a system into increasingly smaller devices, all the way down to a single chip, which added the System-on-Chip (SoC) concept to the electronics world. By way of an example of a SoC, I will explain the Zynq-7000 all-programmable SoC. It consists of two hard processors, programmable logic (PL), ADC blocks and many other features all in one silicon chip.

Before the invention of the Zynq, processors were coupled with a Field Programmable Gate Array (FPGA) which made communication between the Programmable Logic (PL) and Processing System (PS) complicated. The Zynq architecture, as the latest generation of Xilix’s all-programmable System-on-Chip (SoC) families, combines a dual-core ARM Cortex-A9 with a traditional (FPGA). The interface between the different elements within the Zynq architecture is based on the Advanced eXtensible Interface (AXI) standard, which provides for high bandwidth and low latency connections.

Before implementing the ARM processor inside the Zynq device, users were using a soft core processor such as Xilinx’s Microblaze. The main advantage of using Microblaze was, and remains, the flexibility of the processor instances within a design. On the other hand, the inclusion of hard processor in Zynq delivers significant performance improvements. Also, by simplifying the system to a single chip, the overall cost and physical size of the device are reduced.

Zynq Design Flow

The design flow for the Zynq architecture has some steps in common with a regular FPGA. The first stage is to define the specifications and requirements of the system. Next, during the system design stage, the different tasks (functions) are assigned to implementation in either PL or PS which is called task partitioning. This stage is important because the performance of the overall system will depend on tasks/functions being assigned for implementation in the most appropriate technology: hardware or software. For the rest of this article, visit the Aldec Design and Verification Blog.