Search results
Results from the WOW.Com Content Network
Minimal instruction set computer (MISC) is a central processing unit (CPU) architecture, usually in the form of a microprocessor, with a very small number of basic operations and corresponding opcodes, together forming an instruction set. Such sets are commonly stack-based rather than register-based to reduce the size of operand specifiers.
The MIPS architecture provides a specific example for a machine code whose instructions are always 32 bits long. [5]: 299 The general type of instruction is given by the op (operation) field, the highest 6 bits. J-type (jump) and I-type (immediate) instructions are fully specified by op.
(In the examples that follow, a, b, and c are (direct or calculated) addresses referring to memory cells, while reg1 and so on refer to machine registers.) C = A+B 0-operand (zero-address machines), so called stack machines: All arithmetic operations take place using the top one or two positions on the stack: [9] push a, push b, add, pop c.
A microprocessor is a computer 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).
In computing, an opcode (abbreviated from operation code) [1] [2] 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 ...
An interrupt function to the host microprocessor. An on-chip FIFO buffer for both incoming and outgoing data; this gives the host system more time to respond to an interrupt generated by the UART, without loss of data. Both the computer hardware and software interface of the 16550 are backward compatible with the earlier 8250 UART and 16450 UART.
This was an early example of a medium-scale integrated circuit. Another popular chip was the SCN2651 from the Signetics 2650 family. An example of an early 1980s UART was the National Semiconductor 8250 used in the original IBM PC's Asynchronous Communications Adapter card. [5] In the 1990s, newer UARTs were developed with on-chip buffers.
The MOS Technology 6502 is an example of a microprocessor using a PLA for instruction decode and sequencing. The PLA is visible in photomicrographs of the chip, [12] and its operation can be seen in the transistor-level simulation. Microprogramming is still used in modern CPU designs.