Description
The AT45DB321B is a 2.7-volt only, serial interface Flash memory ideally suited for a wide variety of digital voice-, image-, program code- and data-storage applications. Its 34,603,008 bits of memory are organized as 8192 pages of 528 bytes each. In addition to the main memory, the AT45DB321B also contains two SRAM data buffers of 528 bytes each. The buffers allow receiving of data while a page in the main memory is being reprogrammed, as well as reading or writing a continuous data stream. EEPROM emulation (bit or byte alterability) is easily handled with a self-con tained three step Read-Modify-Write operation. Unlike conventional Flash memories that are accessed randomly with multiple address lines and a parallel interface, the DataFlash uses a SPI serial interface to sequentially access its data. DataFlash sup ports SPI mode 0 and mode 3. The simple serial interface facilitates hardware layout, increases system reliability, minimizes switching noise, and reduces package size and active pin count. The device is optimized for use in many commercial and industrial applications where high density, low pin count, low voltage, and low power are essential. The device operates at clock frequencies up to 20 MHz with a typical active read current consumption of 4 mA.

Features
• Single 2.7V - 3.6V Supply
• Serial Peripheral Interface (SPI) Compatible
• 20 MHz Max Clock Frequency
• Page Program Operation
   – Single Cycle Reprogram (Erase and Program)
   – 8192 Pages (528 Bytes/Page) Main Memory
• Supports Page and Block Erase Operations
• Two 528-byte SRAM Data Buffers – Allows Receiving of Data while Reprogramming of Nonvolatile Memory
• Continuous Read Capability through Entire Array
   – Ideal for Code Shadowing Applications
• Low Power Dissipation
   – 4 mA Active Read Current Typical
   – 2 µA CMOS Standby Current Typical
• Hardware Data Protection Feature
• 100% Compatible to AT45DB321
• 5.0V-tolerant Inputs: SI, SCK, CS, RESET and WP Pins
• Commercial and Industrial Temperature Ranges