Description
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 264- bytes 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.

Features
• Single 4.5V - 5.5V Supply
• Serial Interface Architecture
• Page Program Operation
    – Single Cycle Reprogram (Erase and Program)
    – 1024 Pages (264 Bytes/Page) Main Memory
• Two 264-Byte SRAM Data Buffers – Allows Receiving of Data while Reprogramming of Nonvolatile Memory
• Internal Program and Control Timer
• Fast Page Program Time – 7 ms Typical
• 80 µs Typical Page to Buffer Transfer Time
• Low Power Dissipation
    – 15 mA Active Read Current Typical
    – 15 µA CMOS Standby Current Typical
• 10 MHz Max Clock Frequency
• Hardware Data Protection Feature
• Serial Peripheral Interface (SPI) Compatible – Modes 0 and 3
• CMOS and TTL Compatible Inputs and Outputs
• Commercial and Industrial Temperature Ranges