Microchip Technology AT17F040-30CU

Overview

AT17F040-30CU from Microchip Technology (formerly Atmel) is a 4-Mbit FPGA configuration PROM designed for serial master-mode loading of SRAM-based FPGAs. It delivers 4,194,304 × 1-bit storage, supports 33 MHz serial download speed, operates at 3.3 V ±10%, and features 5.0 V-tolerant I/O pins. It enables single-device multi-bitstream reconfiguration in industrial FPGA systems including Xilinx Spartan® and Virtex®, Altera® FLEX®, and Atmel AT40K/AT94K devices.

For engineers reviewing the AT17F040-30CU datasheet, AT17F040-30CU pinout, AT17F040-30CU application, or AT17F040-30CU equivalent, key selection criteria include cascading CEO output capability, 2-wire ISP programming support, PAGE_EN-controlled 4-page memory partitioning, low-power standby current (<1 mA), and compatibility with legacy AT24C EEPROM interfaces.

Technical Context

The AT17F040-30CU implements a dedicated flash-based serial configuration architecture with integrated power-on reset, address counter logic, and tri-state DATA output control via CE and RESET/OE. Its block diagram confirms separation between serial download logic (for FPGA configuration) and 2-wire ISP programming logic (enabled by SER_EN low).

It supports two distinct operational modes: FPGA master serial mode (SER_EN = high) with CLK-driven bitstream streaming and cascaded CEO daisy-chaining, and in-system programming mode (SER_EN = low) using A2 as chip-select on a 2-wire bus. Page select inputs PAGESEL[1:0] only affect address decoding when PAGE_EN is asserted high.

Key Specifications

Pinout & Package

AT17F040-30CU is packaged in an 8-pad Leadless Array Package (LAP), 6 mm × 6 mm × 1.04 mm body, pin-compatible with 8-lead SOIC/VOIC footprints. The package uses Sn (lead-free/halogen-free) finish and complies with RoHS.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT17F040-30CU, XC18V04 offers JTAG-standardized programming but sacrifices hardware-level page switching, while AT17F040-30JU retains identical functionality with mechanical and layout trade-offs-making the CU variant optimal for space-constrained industrial PCBs requiring surface-mount reliability.

Availability

AT17F040-30CU is available at Aetrix Electronics and suitable for industrial automation, FPGA-based embedded vision, and reconfigurable motor control systems requiring stable component supply across extended product lifecycles.

Supply support for AT17F040-30CU 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

Microchip Technology acquired Atmel in 2016 and maintains full support for legacy Atmel FPGA configuration products including the AT17F series.

The AT17F product line was designed specifically for reliable, low-pin-count serial configuration of SRAM-based FPGAs in industrial and embedded applications where long-term availability and field reprogrammability are critical.

FAQ

What is the primary function of the AT17F040-30CU in an FPGA system?

The AT17F040-30CU serves as a serial configuration PROM that loads bitstream data into SRAM-based FPGAs during power-up or reset. It operates in master serial mode, synchronized to the FPGA's CCLK signal, and delivers the 4-Mbit configuration file directly to the FPGA's DIN pin. Its design eliminates the need for external controllers in standard FPGA boot sequences, and the AT17F040-30CU integrates features such as CEO daisy-chaining and page-select logic to extend configurability beyond basic loading.

Does the AT17F040-30CU support in-system programming (ISP), and how is it enabled?

Yes, the AT17F040-30CU supports 2-wire in-system programming via dedicated ISP mode. This mode is activated by driving the SER_EN pin low, which repurposes the CEO pin as A2 chip-select and configures DATA and CLK as bidirectional 2-wire bus lines. Programming occurs at nominal 3.3 V supply with internally generated high-voltage pulses-no external VPP required. The AT17F040-30CU is compatible with Atmel ATDH2200E and third-party programmers supporting this protocol.

How does the PAGE_EN and PAGESEL[1:0] feature work in the AT17F040-30CU?

When PAGE_EN is driven high, the AT17F040-30CU divides its 4-Mbit address space into four 1-Mbit pages. PAGESEL[1:0] selects which page is active during serial download: 00 selects 00000h–0FFFFh, 01 selects 10000h–1FFFFh, 10 selects 20000h–2FFFFh, and 11 selects 30000h–3FFFFh. If PAGE_EN remains low, the full linear address space (00000h–3FFFFh) is used. This feature enables the AT17F040-30CU to store and rapidly switch between up to four independent FPGA configurations without external logic.

What is the role of the CEO pin on the AT17F040-30CU, and how is it used in cascaded configurations?

The CEO (Chip Enable Output) pin on the AT17F040-30CU signals end-of-configuration by driving low when the internal address counter reaches its maximum value. In cascaded setups, CEO of the first AT17F040-30CU connects to the CE input of the second device, enabling automatic handoff of configuration data flow. This eliminates timing-critical external control signals and allows arbitrary expansion of total configuration memory-e.g., two AT17F040-30CU devices provide 8 Mbit of contiguous or partitioned storage for large FPGAs or multi-FPGA systems.

Is the AT17F040-30CU compatible with Xilinx and Altera FPGAs, and what interfaces are required?

Yes, the AT17F040-30CU is explicitly validated for compatibility with Xilinx XC3000/XC4000/XC5200/Spartan®/Virtex® families and Altera FLEX®/APEX™ devices. Interface requirements are minimal: connect AT17F040-30CU DATA to FPGA DIN, CLK to FPGA CCLK, CE to FPGA INIT_B (or equivalent), and RESET/OE to FPGA PROGRAM_B. No level-shifting is needed-the AT17F040-30CU's 5.0 V-tolerant I/O accommodates mixed-voltage signaling, and its timing parameters align with standard FPGA master serial protocols.