||(Double Data Rate) or DDR SDRAM The next generation of the current SDRAM. DDR finds its foundations on the same design core of SDRAM, yet adds advances to enhance its speed capabilities. As a result, DDR allows data to be read on both the rising and the falling edge of the clock, delivering twice the bandwidth of standard SDRAMS. DDR essentially doubles the memory speed from SDRAMs without increasing the clock frequency
||(Dual In-line Memory Module) A printed circuit board with gold or tin/lead contacts and memory devices. A DIMM is similar to a SIMM, but with this primary difference: unlike the leads on either side of a SIMM, which are "tied together" electrically, the leads on either side of a DIMM are electrically independent, ie actually separate circuits which allows for wider and faster data transfer.
||(Dual In-line Package) A form of DRAM component packaging. DIPs can be installed either in sockets or permanently soldered into holes extending into the surface of the printed circuit board. The DIP package was extremely popular when it was common for memory to be installed directly on a computer's motherboard.
||Data mask signal used by SDRAMs to provide byte masking during write operations. There is one DQM signal for every 8 bits of data width.
||(Dynamic Random Access Memory) DRAM is the most common type of memory and is "dynamic" because in order for the memory chip to retain data, it must be refreshed constantly (every few milliseconds). If the cell is not refreshed, the data is lost. DRAM temporarily stores data in a cell composed of a capacitor and a transistor. Each cell contains a specified number of bits. These cells are accessed by row addresses and column addresses.
||(Direct Rambus DRAM)-- a totally new RAM architecture, complete with bus mastering (the Rambus Channel Master) and a new pathway (the Rambus Channel) between memory devices (the Rambus Channel Slaves). A single Rambus Channel has the potential to reach 500MBps in burst mode; a 20-fold increase over DRAM.