Search results
Results from the WOW.Com Content Network
An eight-bit processor like the Intel 8008 addresses eight bits, but as this is the full width of the accumulator and other registers, this could be considered either byte-addressable or word-addressable. 32-bit x86 processors, which address memory in 8-bit units but have 32-bit general-purpose registers and can operate on 32-bit items with a ...
If that memory is arranged in a byte-addressable flat address space using 8-bit bytes, then there are 65,536 (2 16) valid addresses, from 0 to 65,535, each denoting an independent 8 bits of memory. If instead it is arranged in a word-addressable flat address space using 32-bit words, then there are 16,384 (2 14 ) valid addresses, from 0 to ...
For example, an 8-bit-byte-addressable machine with a 20-bit address bus (e.g. Intel 8086) can address 2 20 (1,048,576) memory locations, or one MiB of memory, while a 32-bit bus (e.g. Intel 80386) addresses 2 32 (4,294,967,296) locations, or a 4 GiB address space. In contrast, a 36-bit word-addressable machine with an 18-bit address bus ...
These prefixes are more often used for multiples of bytes, as in kilobyte (1 kB = 8000 bit), megabyte (1 MB = 8 000 000 bit), and gigabyte (1 GB = 8 000 000 000 bit). However, for technical reasons, the capacities of computer memories and some storage units are often multiples of some large power of two, such as 2 28 = 268 435 456 bytes.
As an example, on the IBM 7030 [4] ("Stretch"), a floating point instruction can only address words while an integer arithmetic instruction can specify a field length of 1-64 bits, a byte size of 1-8 bits and an accumulator offset of 0-127 bits. In a byte-addressable machine with storage-to-storage (SS) instructions, there are typically move ...
The byte is a unit of digital information that most commonly consists of eight bits. 1 byte (B) = 8 bits (bit).Historically, the byte was the number of bits used to encode a single character of text in a computer [1] [2] and for this reason it is the smallest addressable unit of memory in many computer architectures.
The DEC PDP-10, also 36-bit, had special instructions which allowed memory to be treated as a sequence of fixed-size bit fields or bytes of any size from 1 bit to 36 bits. A one-word sequence descriptor in memory, called a "byte pointer", held the current word address within the sequence, a bit position within a word, and the size of each byte.
The Intel 80286 CPU used a 24-bit addressing scheme. Each memory location was byte-addressable. This results in a total addressable space of 2 24 × 1 byte = 16,777,216 bytes or 16 megabytes. The 286 and later could also function in real mode, which imposed the addressing limits of the 8086 processor. The 286 had support for virtual memory.