From Alvin Despain:

 '148 Patent
27. The '148 patent generally relates to a microprocessor that includes both a processing unit and memory on the same substrate. Providing the processing unit on the same
substrate as the memory provides a significant performance benefit. A processing unit functions by interpreting and executing programmed instructions that are stored in memory. The
instructions typically cause the processing unit to perform some operation on data, such as adding or multiplying data. The data that the processing unit performs the operation on is obtained from memory, and the result is sent to memory. In order to read data from or write data to memory, the processor must send an address to the memory that provides the location of the
data in memory. The path over which the processing unit and the memory communicate is called a bus. The speed at which information travels over this bus greatly impacts the performance of an electronic device such as a computer.
28. The '148 patent teaches increasing this speed by providing the processing unit and the memory on the same substr ate. By providing memory on the same substrate as the processing unit, a direct path is provided between the memory and the processing unit. In the '148 patent, the memory occupies a majority of the active area of the substrate. The active area refers to the portion of the substrate that includes active circuitry.
29. The memory stores both instructions and data that are used by the processing unit. There are many different types of memory. Different examples include dynamic random access
memory ("DRAM"), registers, cache, and latches. These different types of memory vary in their architecture and performance. For example, DRAM is made up of certain arrangements of capacitors and transistors. Registers and cache, on the other hand, typically are implemented as static random access memory ("SRAM") that contains only transistors. Latches are often made
up of flip-flops, which also contain only transistors but in a different configuration than in SRAM. Because of these differences in architecture, latches typically are faster than registers and cache, which in turn are faster than DRAM. Despite these differences in architecture and performance, all of these types of memory have common features. In particular, they all contain memory cells that are each capable of storing a bit of data (i.e. a single "1" or a "0"). Furthermore, they all contain control circuitry that allows information to be read from or written to the memory cells.
30. The '148 patent also teaches using the microprocessor in a multiprocessor environment. An array of microprocessors as described in the '148 patent provides an extremely small but powerful computer. The microprocessors communicate with each other over interface ports that the '148 patent describes as being a serial input/output interface. The '148 patent
teaches that these interface ports can include six lines, some of which are used to transfer data and others which are used to transfer control signals. While these interface ports can be used for communicating with other microprocessors, they can also be used for communication with other devices that are external to the microprocessor.
31. The '148 patent, like the '336 patent, teaches using a ring-oscillator to provide a system clock that is on the same chip as the microprocessor, and which is therefore subject to the same variations in operating conditions, such as temperature and voltage, or from variations in manufacturing.