To achieve a 1GHz operating clock speed in 45nm LP process, the Hummingbird utilizes a semi-custom design flow which involves custom designed circuit/memory structures, a set of customized primitive cells, and the enhanced RTL FastCore and Fast14 high-speed domino logic from Intrinsity in its implementation. A multi-Vdd / multi-frequency design methodology was also used to ensure the Hummingbird can run at a high speed even at the minimum supply voltage of 1.0V. The low power consumption and the high operating clock performance make the Hummingbird an ideal processor core for use in advanced mobile devices.
"The biggest challenge in mobile processor core design and implementation is to achieve high clock speed performance while keeping the power consumption low," said Dr. Jae Cheol Son, Vice President, SOC Platform Development, System LSI Division, Samsung Electronics. "Collaboration between Samsung and Intrinsity combines the best design and implementation technologies in the industry in successfully meeting the aggressive performance and power consumption targets of the Hummingbird. Samsung's forthcoming SOC products which are based on the Hummingbird will enable our customers to add many more advanced processing capabilities to their mobile products without sacrificing battery life."
A highly effective synthesis flow which creates static logic with optimal timing and power was employed to generate the gate-level view of the Hummingbird. With this flow, standard cell gates are placed to minimize wire delay and maximize speed. Highly automated Vt and cell selection flows choose the best gates for speed while balancing power.
Finally, a high performance physical design integration flow which includes automated and optimized bus routing, driving, and re-buffering is used to generate the final design.
FastCore is Intrinsity's enhanced Cortex-A8 processor-based RTL which is cycle-accurate and Boolean equivalent to the original Cortex-A8 RTL specification. While most ARM processor cores are implemented with synthesized static logic and compiled SRAMs, the Hummingbird achieves the 1GHz clock rate in Samsung's 45nm LP process technology through the use of a semi-custom design flow which strategically applies Intrinsity�s proprietary Fast14 1-of-n domino logic (NDL) technology as macros in the timing-critical paths of the Cortex-A8 RTL core. NDL provides low latency conversion between domino logic and static logic which allows NDL to be seamlessly applied to a standard cell synthesized design. NDL provides gates which are 25 to 50 percent faster than static logic gates.