The AT45D021 is a 5-volt only, serial interface Flash memory suitable for in-system reprogramming. Its 2,162,688 bits of memory are organized as 1024 pages of 264bytes each. In addition to the main memory, the AT45D021 also contains two data SRAM buffers of 264-bytes each. The buffers allow receiving of data while a page in the main memory is being reprogrammed. Unlike conventional Flash memories that are accessed randomly with multiple address lines and a parallel interface, the DataFlash uses a serial interface to sequentially access its data. The simple serial interface facilitates hardware layout, increases system reliability, minimizes switching (continued)