AT25DF256 256-Kbit, 1.65V Minimum SPI Serial Flash Memory with Dual-Read Support Features Single 1.65V - 3.6V Supply Serial Peripheral Interface (SPI) Compatible Supports SPI Modes 0 and 3 Supports Dual Output Read 104MHz Maximum Operating Frequency Clock-to-Output (t ) of 6 ns V Flexible, Optimized Erase Architecture for Code + Data Storage Applications Small (256-Byte) Page Erase Uniform 4-Kbyte Block Erase Uniform 32-Kbyte Block Erase Full Chip Erase Hardware Controlled Locking of Protected Sectors via WP Pin 128-byte, One-Time Programmable (OTP) Security Register 64 bytes factory programmed with a unique identifier 64 bytes user programmable Flexible Programming Byte/Page Program (1 to 256 Bytes) Fast Program and Erase Times 1.5ms Typical Page Program (256 Bytes) Time 50ms Typical 4-Kbyte Block Erase Time 350ms Typical 32-Kbyte Block Erase Time Automatic Checking and Reporting of Erase/Program Failures Software Controlled Reset JEDEC Standard Manufacturer and Device ID Read Methodology Low Power Dissipation 200nA Ultra Deep Power Down current (Typical) 5A Deep Power-Down Current (Typical) 25uA Standby current (Typical) 4.5mA Active Read Current (Typical) Endurance: 100,000 Program/Erase Cycles Data Retention: 20 Years Temperature Range:-10C to +85C (1.65V to 3.6V), -40C to +85 (1.7V to 3.6V) Industry Standard Green (Pb/Halide-free/RoHS Compliant) Package Options 8-lead SOIC (150-mil) 8-pad Ultra Thin DFN (2 x 3 x 0.6 mm) 8-lead TSSOP Package DS-25DF256035D2/20171. Description The Adesto AT25DF256 is a serial interface Flash memory device designed for use in a wide variety of high-volume consumer based applications in which program code is shadowed from Flash memory into embedded or external RAM for execution. The flexible erase architecture of the AT25DF256, with its page erase granularity it is ideal for data storage as well, eliminating the need for additional data storage devices. The erase block sizes of the AT25DF256 have been optimized to meet the needs of today s code and data storage applications. By optimizing the size of the erase blocks, the memory space can be used much more efficiently. Because certain code modules and data storage segments must reside by themselves in their own erase regions, the wasted and unused memory space that occurs with large sectored and large block erase Flash memory devices can be greatly reduced. This increased memory space efficiency allows additional code routines and data storage segments to be added while still maintaining the same overall device density. The device also contains a specialized OTP (One-Time Programmable) Security Register that can be used for purposes such as unique device serialization, system-level Electronic Serial Number (ESN) storage, locked key storage, etc. Specifically designed for use in many different systems, the AT25DF256 supports read, program, and erase operations with a wide supply voltage range of 1.65V to 3.6V. No separate voltage is required for programming and erasing. 2. Pin Descriptions and Pinouts Table 2-1. Pin Descriptions Asserted Symbol Name and Function State Type CHIP SELECT: Asserting the CS pin selects the device. When the CS pin is deasserted, the device will be deselected and normally be placed in standby mode (not Deep Power-Down mode), and the SO pin will be in a high-impedance state. When the device is deselected, data will not be accepted on the SI pin. CS Low Input A high-to-low transition on the CS pin is required to start an operation, and a low-to-high transition is required to end an operation. When ending an internally self-timed operation such as a program or erase cycle, the device will not enter the standby mode until the completion of the operation. SERIAL CLOCK: This pin is used to provide a clock to the device and is used to control the flow of data to and from the device. Command, address, and input data present on the SI pin SCK - Input is always latched in on the rising edge of SCK, while output data on the SO pin is always clocked out on the falling edge of SCK. SERIAL INPUT: The SI pin is used to shift data into the device. The SI pin is used for all data input including command and address sequences. Data on the SI pin is always latched in on the rising edge of SCK. With the Dual-Output Read commands, the SI Pin becomes an output pin (I/O ) in 0 conjunction with other pins to allow two bits of data on (I/O ) to be clocked out on every 1-0 falling edge of SCK. SI (I/O ) - Input/Output 0 To maintain consistency with the SPI nomenclature, the SI (I/O ) pin will be referenced as 0 the SI pin unless specifically addressing the Dual-I/O modes in which case it will be referenced as I/O 0. Data present on the SI pin will be ignored whenever the device is deselected (CS is deasserted). AT25DF256 2 DS-25DF256035D2/2017