Brick and Mortar Chip Fabrication

Brick and Mortar Chip Fabrication Martha Allen Kim Chair of the Supervisory Committee: Professor Mark Oskin Computer Science and Engineering While Moore’s Law has advanced the semiconductor and technology industries, it has simultaneously driven up the cost of engineering a chip in a modern silicon process. The result is that fewer and fewer chips are produced in larger and larger volumes, stifling hardware diversity. This thesis introduces brick and mortar chips, which aim to obtain the benefits of Moore’s Law without the financial side effects. Brick and mortar chips are made from small, pre-fabricated hardware components (called bricks) that are bonded in a designerspecified arrangement to a communication backbone chip which serves as the mortar (called the I/O cap). Our research examines several aspects of this chip manufacturing system. We develop a family of functional bricks, demonstrating a methodology for developing families that make efficient use of physical computation and communication resources. For high-performance communication between arbitrary combinations of bricks we propose a polymorphic onchip network. This network allows a single I/O cap to be configured to implement the ideal network for any particular application. We analyze a low-cost, physical component assembly technique called fluidic self-assembly, and find that the chip production rate is intertwined with the architectural design of the components. To minimize application execution time on these partitioned chips, we develop software partitioning and mapping techniques which balance communication costs against computational resource contention. We close with a case study: an analysis of a brick and mortar implementation of a chip multiprocessor. Despite this being a highly latency sensitive design, our measurements indicate a worst case 36% average slowdown in application execution compared to a traditional, monolithic chip. Based on this, our cost analysis, and a survey of related technologies, we conclude that brick and mortar offers the best available performance for its price.