Search results
Results from the WOW.Com Content Network
In CPU design, the use of a sum-addressed decoder (SAD) or sum-addressed memory (SAM) decoder is a method of reducing the latency of the CPU cache access and address calculation (base + offset). This is achieved by fusing the address generation sum operation with the decode operation in the cache SRAM .
An address decoder is also used to select the appropriate one of multiple memory modules or memory chips when a particular address is provided by the processor system's address bus. For this purpose, the memory modules or memory chips have selection inputs, usually referred to as chip select pin (CS) or chip enable pin (CE) pin.
Modern GPU chips may operate data across a 256-bit memory bus (or possibly a 512-bit bus with HBM3 [3]). The Efficeon processor was Transmeta 's second-generation 256-bit VLIW design which employed a software engine to convert code written for x86 processors to the native instruction set of the chip.
Copy data from a memory location or a register to a memory location or a register (a machine instruction is often called move; however, the term is misleading). They are used to store the contents of a register, the contents of another memory location or the result of a computation, or to retrieve stored data to perform a computation on it later.
Memory-mapped I/O is preferred in IA-32 and x86-64 based architectures because the instructions that perform port-based I/O are limited to one register: EAX, AX, and AL are the only registers that data can be moved into or out of, and either a byte-sized immediate value in the instruction or a value in register DX determines which port is the source or destination port of the transfer.
In computing, serial presence detect (SPD) is a standardized way to automatically access information about a memory module.Earlier 72-pin SIMMs included five pins that provided five bits of parallel presence detect (PPD) data, but the 168-pin DIMM standard changed to a serial presence detect to encode more information.
This method uses two memory accesses (one for the page-table entry, one for the byte) to access a byte. First, the page table is looked up for the frame number. Second, the frame number with the page offset gives the actual address. Thus, any straightforward virtual memory scheme would have the effect of doubling the memory access time.
Support for such operations was an upgrade option rather than being a standard feature. Since the VAX's registers were 32 bits wide, a 128-bit operation used four consecutive registers or four longwords in memory. The ICL 2900 Series provided a 128-bit accumulator, and its instruction set included 128-bit floating-point and packed decimal ...