Microchip Technology AT17N256-10PI

Overview

AT17N256-10PI from Atmel is a 256-Kbit serial EEPROM FPGA configuration memory designed for Master Serial mode loading of Xilinx Spartan-II, Spartan-IIE, and Spartan XL FPGAs. It operates at 3.3V ±10%, supports industrial temperature range (−40°C to +85°C), features ≤50 µA standby current, and uses low-power CMOS EEPROM process with 10⁴ write cycles and 20-year data retention at 85°C.

For engineers reviewing the AT17N256-10PI datasheet, AT17N256-10PI pinout, AT17N256-10PI application, or AT17N256-10PI equivalent, this device serves as a drop-in replacement for Xilinx XC17SXXXA/L PROMs in legacy FPGA configuration systems requiring reliable, nonvolatile, serial-programmable memory with tri-state DATA output and SER_EN-controlled ISP capability.

Technical Context

The AT17N256-10PI implements a synchronous serial interface where CLK increments an internal address counter, CE enables data output and counting, and RESET/OE resets the counter and controls DATA tristate. SER_EN must be held high during FPGA configuration but can be pulled low to enter Two-Wire Serial Programming mode.

It interfaces directly with SRAM-based FPGAs without external controllers: DATA drives FPGA DIN, FPGA CCLK drives CLK, and FPGA outputs control CE and RESET/OE. The device supports both active-low reset and active-high output enable logic, programmable via on-chip configuration.

Key Specifications

Pinout & Package

AT17N256-10PI is packaged in an 8-lead PDIP (package code 8P3), 0.300" wide, with lead pitch 0.100", body width 0.365", and JEDEC MS-001 compliant dimensions.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar FPGA configuration memory applications.

Compared with AT17N256-10PI, AT17LV256-10PI offers broader voltage tolerance and slightly higher standby current, while XC17S100A-PC44I sacrifices reprogrammability and package flexibility for OTP security-making AT17N256-10PI the optimal choice for field-serviceable industrial FPGA systems needing PDIP compatibility and ISP support.

Availability

AT17N256-10PI is available at Aetrix Electronics and suitable for industrial PLCs, FPGA-based test instrumentation, legacy Xilinx system maintenance, embedded control boot memory, and safety-critical reconfigurable logic applications requiring stable component supply across extended product lifecycles.

Supply support for AT17N256-10PI includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Atmel Corporation (now part of Microchip Technology) is a semiconductor manufacturer specializing in microcontrollers, nonvolatile memory, and FPGA configuration solutions for industrial, automotive, and communications markets.

The AT17N series was designed specifically to replace Xilinx OTP PROMs in Master Serial FPGA configuration, offering reprogrammability, industrial temperature support, and direct pin compatibility with minimal system integration effort.

FAQ

What is the primary function of the AT17N256-10PI in an FPGA system?

The AT17N256-10PI serves as a serial configuration memory that stores and delivers the bitstream to SRAM-based FPGAs such as Xilinx Spartan-II during power-up or reset. It operates in Master Serial mode, where the FPGA autonomously clocks data from the AT17N256-10PI via its CLK input and loads it into configuration RAM without external intervention.

Does the AT17N256-10PI support in-system programming (ISP)?

Yes, the AT17N256-10PI supports Two-Wire Serial ISP via the SER_EN pin. When SER_EN is pulled low, the device enters ISP mode and accepts programming commands over the DATA and CLK lines using industry-standard programmers or Atmel's ATDH2225 ISP Cable - enabling field updates without removing the AT17N256-10PI from the board.

What is the significance of the "-10PI" suffix in AT17N256-10PI?

The "-10PI" suffix indicates a 10 MHz maximum clock frequency rating and industrial temperature grade (−40°C to +85°C). The "P" denotes 8-lead PDIP packaging, and "I" confirms industrial qualification - distinguishing it from commercial-grade variants like AT17N256-10PC which operate only from 0°C to +70°C.

Can the AT17N256-10PI be used with Spartan-III or Virtex FPGAs?

No - the AT17N256-10PI is explicitly designed and validated for Xilinx Spartan-II, Spartan-IIE, and Spartan XL FPGAs in Master Serial mode. Spartan-III and Virtex families use different configuration protocols (e.g., SelectMAP or JTAG), and the AT17N256-10PI lacks the necessary interface logic or timing compliance for those architectures.

How does the AT17N256-10PI handle power-on initialization?

Upon power-up, the AT17N256-10PI automatically resets its internal address counter to zero. This ensures the FPGA always reads the configuration bitstream from the first bit, guaranteeing deterministic startup behavior. No external reset signal is required unless a mid-operation reload is needed - in which case driving RESET/OE low achieves the same effect.