AT17C256-10SC

Overview

The AT17C256-10SC is a 256K-bit (262,144 x 1-bit) serial EEPROM designed for FPGA configuration. It operates at 5V nominal and supports industrial temperature ranges (-40°C to +85°C). The device features a simple 2-wire serial interface for in-system programming and utilizes a master serial mode to automatically load configuration programs into FPGAs upon power-up. It includes programmable reset polarity, write protection, and cascading capabilities via the CEO output.

Feature Summary

• Designed specifically to store configuration programs for Field Programmable Gate Arrays (FPGAs)
• Supports in-system programming via a simple 2-wire serial bus interface
• Features programmable reset polarity and internal write-protection mechanisms
• Enables cascading of multiple devices to support higher-density FPGA arrays

Applications

• Configuration memory for Atmel AT6000 and AT40K series FPGAs
• Configuration storage for Altera FLEX devices
• Configuration storage for Xilinx XC3000, XC4000, and SPARTAN FPGAs
• Configuration storage for Lucent ORCA and Motorola MPA1000 FPGAs

Procurement Notes

Verify that the specific ordering suffix corresponds to the required package type and operating temperature range. Confirm compatibility with the target FPGA's master serial mode requirements. Ensure the supply voltage matches the 5V nominal specification for the AT17C variant. Check for any legacy status or obsolescence notices from the manufacturer.

Selection Notes

Select this component when a non-volatile memory solution is required for FPGA configuration in industrial environments. It is suitable for designs requiring cascading capabilities to expand memory capacity beyond single-device limits. Consider the 8-pin SOIC package for space-constrained surface-mount applications. Verify interface compatibility with the specific FPGA model being configured.

Part Context

This part belongs to the low-density AT17 Series of FPGA Configuration EEPROMs. The family includes 64K, 128K, and 256K bit densities. The 'C' designation indicates 5V operation, while 'LV' denotes 3.3V versions. These devices serve as configurators, providing cost-effective and easy-to-use memory solutions for various FPGA architectures.

Replacement Considerations

AT17LV256-10SC

FAQ

How does the AT17C256 handle external resets during configuration?

The device supports two connection conditions for the RESET/OE pin. If driven by the FPGA CON pin, it may lose sync during external resets unless the reset polarity is programmed active High. Alternatively, driving RESET/OE from the FPGA RESET input clears the address pointer, ensuring reconfiguration starts correctly.

What is the function of the CEO pin?

The Chip Enable Output (CEO) pin is asserted Low on the clock cycle following the last bit read from the memory. This signal enables cascading by allowing the next EEPROM in the chain to enable its data output driver.