A central processing unit (CPU)—also called a central processor or Microprocessor or main processor—is the most important processor in a given computer. Its electronic circuitry executes instructions of a computer program, such as arithmetic, logic, controlling, and input/output (I/O) operations. This role contrasts with that of external components, such as main memory and I/O circuitry, and specialized coprocessors such as graphics processing units (GPUs).
In digital computers, an interrupt is a request for the processor to interrupt currently executing code, so that the event can be processed in a timely manner. If the request is accepted, the processor will suspend its current activities, save its state, and execute a function called an interrupt handler to deal with the event. This interruption is often temporary, allowing the software to resume normal activities after the interrupt handler finishes, although the interrupt could instead indicate a fatal error.
In computer programming, machine code is computer code consisting of machine language instructions, which are used to control a computer's central processing unit (CPU). Although decimal computers were once common, the contemporary marketplace is dominated by binary computers; for those computers, machine code is "the binary representation of a computer program which is actually read and interpreted by the computer. A program in machine code consists of a sequence of machine instructions ."
In computer science, an instruction set architecture (ISA), also called computer architecture, is an abstract model of a computer. A device that executes instructions described by that ISA, such as a central processing unit (CPU), is called an implementation.
A debugger or debugging tool is a computer program used to test and debug other programs. The main use of a debugger is to run the target program under controlled conditions that permit the programmer to track its execution and monitor changes in computer resources that may indicate malfunctioning code. Typical debugging facilities include the ability to run or halt the target program at specific points, display the contents of memory, CPU registers or storage devices, and modify memory or register contents in order to enter selected test data that might be a cause of faulty program execution.
ARM is a family of RISC instruction set architectures (ISAs) for computer processors. Arm Ltd. develops the ISAs and licenses them to other companies, who build the physical devices that use the instruction set. It also designs and licenses cores that implement these ISAs.
In-circuit emulation (ICE) is the use of a hardware device or in-circuit emulator used to debug the software of an embedded system. It operates by using a processor with the additional ability to support debugging operations, as well as to carry out the main function of the system. Particularly for older systems, with limited processors, this usually involved replacing the processor temporarily with a hardware emulator: a more powerful although more expensive version. It was historically in the form of bond-out processor which has many internal signals brought out for the purpose of debugging. These signals provide information about the state of the processor.
Simics is a full-system simulator or virtual platform used to run unchanged production binaries of the target hardware. Simics was originally developed by the Swedish Institute of Computer Science (SICS), and then spun off to Virtutech for commercial development in 1998. Virtutech was acquired by Intel in 2010. Currently, Simics is provided by Intel in a public release and sold commercially by Wind River Systems, which was in the past a subsidiary of Intel.
Memory protection is a way to control memory access rights on a computer, and is a part of most modern instruction set architectures and operating systems. The main purpose of memory protection is to prevent a process from accessing memory that has not been allocated to it. This prevents a bug or malware within a process from affecting other processes, or the operating system itself. Protection may encompass all accesses to a specified area of memory, write accesses, or attempts to execute the contents of the area. An attempt to access unauthorized memory results in a hardware fault, e.g., a segmentation fault, storage violation exception, generally causing abnormal termination of the offending process. Memory protection for computer security includes additional techniques such as address space layout randomization and executable space protection.
JTAG is an industry standard for verifying designs and testing printed circuit boards after manufacture.
In software development, a breakpoint is an intentional stopping or pausing place in a program, put in place for debugging purposes. It is also sometimes simply referred to as a pause.
A branch is an instruction in a computer program that can cause a computer to begin executing a different instruction sequence and thus deviate from its default behavior of executing instructions in order. Branch may also refer to the act of switching execution to a different instruction sequence as a result of executing a branch instruction. Branch instructions are used to implement control flow in program loops and conditionals.
In electronics, computer science and computer engineering, microarchitecture, also called computer organization and sometimes abbreviated as µarch or uarch, is the way a given instruction set architecture (ISA) is implemented in a particular processor. A given ISA may be implemented with different microarchitectures; implementations may vary due to different goals of a given design or due to shifts in technology.
In software engineering, profiling is a form of dynamic program analysis that measures, for example, the space (memory) or time complexity of a program, the usage of particular instructions, or the frequency and duration of function calls. Most commonly, profiling information serves to aid program optimization, and more specifically, performance engineering.
In integrated circuit design, hardware emulation is the process of imitating the behavior of one or more pieces of hardware with another piece of hardware, typically a special purpose emulation system. The emulation model is usually based on a hardware description language source code, which is compiled into the format used by emulation system. The goal is normally debugging and functional verification of the system being designed. Often an emulator is fast enough to be plugged into a working target system in place of a yet-to-be-built chip, so the whole system can be debugged with live data. This is a specific case of in-circuit emulation.
A computer architecture simulator is a program that simulates the execution of computer architecture.
In computing, an emulator is hardware or software that enables one computer system to behave like another computer system. An emulator typically enables the host system to run software or use peripheral devices designed for the guest system. Emulation refers to the ability of a computer program in an electronic device to emulate another program or device.
MikroSim is an educational software computer program for hardware-non-specific explanation of the general functioning and behaviour of a virtual processor, running on the Microsoft Windows operating system. Devices like miniaturized calculators, microcontroller, microprocessors, and computer can be explained on custom-developed instruction code on a register transfer level controlled by sequences of micro instructions (microcode). Based on this it is possible to develop an instruction set to control a virtual application board at higher level of abstraction.
RISC-V is an open standard instruction set architecture (ISA) based on established reduced instruction set computer (RISC) principles. Unlike most other ISA designs, RISC-V is provided under royalty-free open-source licenses. Many companies are offering or have announced RISC-V hardware; open source operating systems with RISC-V support are available, and the instruction set is supported in several popular software toolchains.
The Hack Computer is a theoretical computer design created by Noam Nisan and Shimon Schocken and described in their book, The Elements of Computing Systems: Building a Modern Computer from First Principles. In using the term “modern”, the authors refer to a digital, binary machine that is patterned according to the von Neumann architecture model.
