Minimal instruction set computer
Encyclopedia
Minimal Instruction Set Computer (MISC) is a processor
architecture with a very small number of basic operations and corresponding opcode
s. Such instruction set
s are commonly stack based rather than register based to reduce the size of operand
specifiers. Such a stack machine
architecture is inherently simpler since all instructions operate on the top-most stack entries. A result of this is a smaller instruction set, a smaller and faster instruction decode unit, and overall faster operation of individual instructions. The downside is that instructions tend to have more sequential dependencies, reducing instruction-level parallelism. MISC architectures have much in common with the Forth programming language and the Java Virtual Machine
.
Probably the most commercially successful MISC was the INMOS transputer
.
Microprocessor
A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...
architecture with a very small number of basic operations and corresponding opcode
Opcode
In computer science engineering, an opcode is the portion of a machine language instruction that specifies the operation to be performed. Their specification and format are laid out in the instruction set architecture of the processor in question...
s. Such instruction set
Instruction set
An instruction set, or instruction set architecture , is the part of the computer architecture related to programming, including the native data types, instructions, registers, addressing modes, memory architecture, interrupt and exception handling, and external I/O...
s are commonly stack based rather than register based to reduce the size of operand
Operand
In mathematics, an operand is the object of a mathematical operation, a quantity on which an operation is performed.-Example :The following arithmetic expression shows an example of operators and operands:3 + 6 = 9\;...
specifiers. Such a stack machine
Stack machine
A stack machine may be* A real or emulated computer that evaluates each sub-expression of a program statement via a pushdown data stack and uses a reverse Polish notation instruction set....
architecture is inherently simpler since all instructions operate on the top-most stack entries. A result of this is a smaller instruction set, a smaller and faster instruction decode unit, and overall faster operation of individual instructions. The downside is that instructions tend to have more sequential dependencies, reducing instruction-level parallelism. MISC architectures have much in common with the Forth programming language and the Java Virtual Machine
Java Virtual Machine
A Java virtual machine is a virtual machine capable of executing Java bytecode. It is the code execution component of the Java software platform. Sun Microsystems stated that there are over 4.5 billion JVM-enabled devices.-Overview:...
.
Probably the most commercially successful MISC was the INMOS transputer
INMOS transputer
The transputer was a pioneering microprocessor architecture of the 1980s, featuring integrated memory and serial communication links, intended for parallel computing. It was designed and produced by Inmos, a British semiconductor company based in Bristol....
.
See also
- Complex instruction set computerComplex instruction set computerA complex instruction set computer , is a computer where single instructions can execute several low-level operations and/or are capable of multi-step operations or addressing modes within single instructions...
(CISC) - Reduced instruction set computerReduced instruction set computerReduced instruction set computing, or RISC , is a CPU design strategy based on the insight that simplified instructions can provide higher performance if this simplicity enables much faster execution of each instruction. A computer based on this strategy is a reduced instruction set computer...
(RISC) - One instruction set computerOne instruction set computerA one instruction set computer , sometimes called an ultimate reduced instruction set computer , is an abstract machine that uses only one instruction – obviating the need for a machine language opcode...
(OISC) - Zero instruction set computerZero Instruction Set ComputerIn computer science, ZISC stands for Zero Instruction Set Computer, which refers to a chip technology based on pure pattern matching and absence of instructions in the classical sense...
(ZISC)
External links
- Forth MISC chip designs
- seaForth-24 - the next to latest multi-core MISC design from Chuck Moore
- Green Arrays - the latest multi-core MISC design from Chuck Moore
- MISC variants