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Random Logic
Random logic is a semiconductor circuit design technique that translates high-level logic descriptions directly into hardware features such as AND and OR gates. The name derives from the fact that few easily discernible patterns are evident in the arrangement of features on the chip and in the interconnects between them. In VLSI chips, random logic is often implemented with standard cells and gate arrays. Random logic accounts for a large part of the circuit design in modern microprocessors. Compared to microcode, another popular design technique, random logic offers faster execution of processor opcode In computing, an opcode (abbreviated from operation code) is an enumerated value that specifies the operation to be performed. Opcodes are employed in hardware devices such as arithmetic logic units (ALUs), central processing units (CPUs), and ...s, provided that processor speeds are faster than memory speeds. A disadvantage is that it is difficult to design random logic circui ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Cell
In semiconductor design, standard-cell methodology is a method of designing application-specific integrated circuits (ASICs) with mostly digital-logic features. Standard-cell methodology is an example of design abstraction, whereby a low-level very-large-scale integration ( VLSI) layout is encapsulated into an abstract logic representation (such as a NAND gate). Cell-based methodology – the general class to which standard cells belong – makes it possible for one designer to focus on the high-level (logical function) aspect of digital design, while another designer focuses on the implementation (physical) aspect. Along with semiconductor manufacturing advances, standard-cell methodology has helped designers scale ASICs from comparatively simple single-function ICs (of several thousand gates), to complex multi-million gate system-on-a-chip (SoC) devices. Construction of a standard cell A standard cell is a group of transistor and interconnect structures that provides a bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gate Array
A gate array is an approach to the design and manufacture of application-specific integrated circuits (ASICs) using a semiconductor device fabrication, prefabricated chip with components that are later interconnected into logic devices (e.g. NAND gates, Flip-flop (electronics), flip-flops, etc.) according to custom order by adding metal interconnect layers in the factory. It was popular during the upheaval in the semiconductor industry in the 1980s, and its usage declined by the end of the 1990s. Similar technologies have also been employed to design and manufacture analog, analog-digital, and structured arrays, but, in general, these are not called gate arrays. Gate arrays have also been known as uncommitted logic arrays ('ULAs'), which also offered linear circuit functions, and ''semi-custom chips''. History Development Gate arrays had several concurrent development paths. Ferranti in the UK pioneered commercializing bipolar transistor, bipolar ULA technology, offering c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microprocessor
A microprocessor is a computer processor (computing), processor for which the data processing logic and control is included on a single integrated circuit (IC), or a small number of ICs. The microprocessor contains the arithmetic, logic, and control circuitry required to perform the functions of a computer's central processing unit (CPU). The IC is capable of interpreting and executing program instructions and performing arithmetic operations. The microprocessor is a multipurpose, Clock signal, clock-driven, Processor register, register-based, digital integrated circuit that accepts binary code, binary data as input, processes it according to instruction (computing), instructions stored in its computer memory, memory, and provides results (also in binary form) as output. Microprocessors contain both combinational logic and sequential logic, sequential digital logic, and operate on numbers and symbols represented in the binary number system. The integration of a whole CPU on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microcode
In processor design, microcode serves as an intermediary layer situated between the central processing unit (CPU) hardware and the programmer-visible instruction set architecture of a computer. It consists of a set of hardware-level instructions that implement the higher-level machine code instructions or control internal finite-state machine sequencing in many digital processing components. While microcode is utilized in Intel and AMD general-purpose CPUs in contemporary desktops and laptops, it functions only as a fallback path for scenarios that the faster hardwired control unit is unable to manage. Housed in special high-speed memory, microcode translates machine instructions, state machine data, or other input into sequences of detailed circuit-level operations. It separates the machine instructions from the underlying electronics, thereby enabling greater flexibility in designing and altering instructions. Moreover, it facilitates the construction of complex multi-step inst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opcode
In computing, an opcode (abbreviated from operation code) is an enumerated value that specifies the operation to be performed. Opcodes are employed in hardware devices such as arithmetic logic units (ALUs), central processing units (CPUs), and software instruction sets. In ALUs, the opcode is directly applied to circuitry via an input signal bus. In contrast, in CPUs, the opcode is the portion of a machine language instruction that specifies the operation to be performed. CPUs Opcodes are found in the machine language instructions of CPUs as well as in some abstract computing machines. In CPUs, an opcode may be referred to as an instruction machine code, instruction code, instruction syllable, instruction parcel, or opstring. For any particular processor (which may be a general CPU or a more specialized processing unit), the opcodes are defined by the processor's instruction set architecture (ISA). They can be described using an opcode table. The types of operations may in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
