Q. Illustrate Cache DRAM?

Cache DRAM (CDRAM) which is developed by Mitsubishi integrates a tiny SRAM cache (16Kb) on a generic DRAM chip. SRAM on the CDRAM can be used in two ways. First it can be used like true cache comprising of a number of 64-bit line. Cache mode of CDRAM is effective for ordinary random access to memory. 

SRAM on CDRAM can also be used like a buffer to support serial access of a block of data.  For illustration to refresh a bit-mapped screen CDRAM can prefetch the data from DRAM into SRAM buffer. Following accesses to chip may result in accesses solely to SRAM.