What is the difference of SD ram and DDR ram?
SDRAM – Synchronous Dynamic RAM (volatile memory) DDR RAM – Double Data Rate RAM (volatile memory) SDRAM is a type of memory that’s synchronized to the clock speed of your memory bus. DDR RAM is a type of SDRAM that operates by signaling twice for each clock tick thereby doubling the rate that data travels through the memory bus. SD flash memory* – Secure Digital (SD) is a flash (non-volatile) memory card format developed by Matsushita, SanDisk and Toshiba for use in portable devices, including digital cameras, handheld computers, PDAs and GPS units. As of 2006, SD card capacities include 8, 16, 32, 64, 128, 256, and 512 MB, 1, 2, 4, 6, 8 GB (4-32 GB: SDHC)[1].
SDRAM means synchronous dynamic random access memory which is a type of solid state computer memory. Other dynamic random access memories (DRAM) have an asynchronous interface which means that it reacts as quickly as possible to changes in control inputs. SDRAM has a synchronous interface, meaning that it waits for a clock signal before responding to its control inputs. It is synchronized with the computer’s system bus, and thus with the processor. The clock is used to drive an internal finite state machine that pipelines incoming instructions. This allows the chip to have a more complex pattern of operation than DRAM which does not have synchronizing control circuits. Pipelining means that the chip can accept a new instruction before it has finished processing the previous one. In a pipelined write, the write command can be immediately followed by another instruction without waiting for the data to be written to the memory array. In a pipelined read, the requested data appears a fixed
