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 ...
For instance, a computer said to be "32-bit" also usually allows 32-bit memory addresses; a byte-addressable 32-bit computer can address 2 32 = 4,294,967,296 bytes of memory, or 4 gibibytes (GiB). This allows one memory address to be efficiently stored in one word. However, this does not always hold true.
The smallest unit of addressable and writable memory is the 8-bit byte. Bytes can also be held in the lower half of registers R0 through R5. 16-bit words are stored little-endian with least significant bytes at the lower address. Words are always aligned to even memory addresses. Words can be held in registers R0 through R7.
The address and value parameters may contain expressions, as long as the evaluated expressions correspond to valid memory addresses or values, respectively.A valid address in this context is an address within the computer's address space, while a valid value is (typically) an unsigned value between zero and the maximum unsigned number that the minimum addressable unit (memory cell) may hold.
Past hardware had a CISC instruction set with 48-bit addressing, while current hardware is 64-bit PowerPC/Power ISA. In the PowerPC/Power ISA implementation, the first four bytes contain information used to identify the type of the object being referenced, and the final eight bytes are used as a virtual memory address. [13]
It also has some additional power, such as the ability to efficiently count the number of bits that are set. The Boost C++ Libraries provide a dynamic_bitset class [4] whose size is specified at run-time. The D programming language provides bit arrays in its standard library, Phobos, in std.bitmanip.
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 ...
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.