sentences:  Embedded DRAM requires DRAM cell designs that can be fabricated without preventing the fabrication of fast-switching transistors used in high-performance logic, and modification of the basic logic-optimized process technology to accommodate the process steps required to build DRAM cell structures.Since the fundamental DRAM cell and array has maintained the same basic structure for many years, the types of DRAM are mainly distinguished by the many different interfaces for communicating with DRAM chips.The original DRAM, now known by the retronym ""asynchronous DRAM"" was the first type of DRAM in use.