Description
The AT45D021A 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 AT45D021A also contains two SRAM data 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
• 100% Compatible to AT45D021
• 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
• Optional Page and Block Erase Operations
• Two 264-byte SRAM Data Buffers – Allows Receiving of Data while Reprogramming of Nonvolatile Memory
• Continuous Read Capability through Entire Array
• Internal Program and Control Timer
• Low Power Dissipation
    – 15 mA Active Read Current Typical
    – 10 µA CMOS Standby Current Typical
• 15 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