Accelerating system integration by enhancing hardware, firmware, and co-simulation

System integration of an IBM eServer™ z990 begins when a z990 book, which houses the main processors, memory, and I/O adapters, is installed in a z990 frame, Licensed Internal Code is “booted” in the service element (SE), and power is turned on. This initial system “bringup,” also referred to as post-silicon integration, is composed of three major steps: initializing the chips, loading embedded code (firmware) into the system, and starting an initial program load (IPL) of an operating system. These processes are serialized, and verification of the majority of the system components cannot begin until they are complete. Therefore, it is important to shorten this critical time period by improving the quality of the integrated components through more comprehensive verification prior to manufacturing. This enhanced coverage is focused on verifying the interaction between the hardware components and firmware (often referred to as hardware and software co-simulation). Verification of the activities of these components first occurs independently and culminates in a pre-silicon system integration process, or virtual power-on (VPO). This paper focuses primarily on the hardware subsystem verification of the CLK chip [which is the interface between the central electronic complex (CEC) and the service element (SE)] and on enhanced co-simulation. It also considers the various environments (collections of hardware simulation models, firmware, execution time control code, and test cases to stimulate model behavior), with their advantages and disadvantages. Finally, it discusses the results of the improved comprehensive simulation effort with respect to system integration for the z990.