Reliable SPI Connectivity: AXI to SPI IP Core for FPGA Designs

In modern embedded systems, connecting your FPGA design to SPI-based peripherals should be simple, robust, and vendor-agnostic.

Sital Technology’s AXI to SPI IP core delivers exactly that — a straightforward and dependable bridge between the AXI bus and SPI interfaces, ideal for integrating with Sital’s own SPI cards.

What Is the AXI to SPI?

The AXI to SPI is a fully portable IP core designed to work across all major FPGA technologies. It hooks directly into your design’s AXI backbone while routing SPI signals to the FPGA pins.

It supports both Single SPI and Dual SPI modes — with no software drivers required.

This driverless approach means quicker integration, reduced development effort, and freedom from vendor lock-in.

Whether you’re working with Xilinx, Intel (Altera), Lattice, or Microchip FPGAs, the AXI to SPI gives you maximum flexibility and is easy to adapt across future projects.

Why Choose AXI to SPI Over Vendor-Supplied SPI Masters?

Unlike traditional vendor-specific SPI master controllers that often rely on software drivers and fixed configurations, the AXI to SPI offers:

Driver-free AXI-to-SPI access
Automatic switching between Single and Dual SPI modes
2MB memory-mapped interface with mode control via address bits
Full portability across FPGA families with zero redesign

This makes AXI to SPI ideal for developers looking to simplify hardware-software integration while building systems that are easy to maintain and evolve.

Get the IP Core – Included Free with Any SPI Card Purchase

Key Features at a Glance:

Memory Mapping: 2MB mapped at address 0x200000 on the AXI bus.
Mode Selection via Address Bits:
- 11 for Single SPI (backward compatible)
- 01 for Dual SPI
- 00 reserved for future Quad SPI support
Clock Control:
- SPI clock derived from Axi_aclk (up to 50 MHz)
- Suitable for high-speed designs with proper trace layout
Easy Integration:
- Supplied with two VHDL files for all FPGA P&R tools:
  - AXI4_Dual_SPI_Pipeline_Master.vhd
  - Modgen_specifics_sital.vhd

Real-World Example: Xilinx MPSoC in Vivado

In a live implementation using Xilinx’s MPSoC platform and Vivado, the IP was connected to a system running at 100 MHz.

A recorded Single SPI write cycle demonstrated efficient AXI transactions and solid timing, with each SPI cycle taking about 1.3 µs at 25 MHz — proving the design’s speed and consistency.

Ready to Integrate?

Sital’s AXI to SPI IP is built for performance, simplicity, and portability.

If you need reliable SPI communication without the burden of vendor-specific tools or driver development, this IP core is ready to go.

👉 Contact us for integration support.

AXI To SPI IP Core For FPGA Designs: A Driverless, Portable Bridge From The AXI Bus To Single And Dual SPI, Vendor-Agnostic Across Xilinx, Intel, Lattice, And Microchip

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Sital’s AXI to SPI IP core carries the same validated bridge across Xilinx, Intel (Altera), Lattice, and Microchip FPGAs with no software driver in the path. It connects your design’s AXI backbone to single- and dual-SPI and routes the SPI signals directly to the FPGA pins.

Most vendor-supplied SPI masters work the other way. They depend on software drivers, fixed configurations, and FIFO logic that you re-validate every time the target device changes. Sital built the AXI to SPI core to take that work off your plate.

Sital writes the core in vendor-independent VHDL and designs it for DO-254 and DO-178 certifiability, including DAL A. Like every Sital product, it is proudly made in the USA.

TL;DR Quick Answers

AXI To SPI IP Core For FPGA Designs

Sital’s AXI to SPI IP core is a driverless, memory-mapped bridge that connects an FPGA’s AXI bus to single and dual SPI devices and routes the SPI signals directly to the FPGA pins. One vendor-independent VHDL source runs on Xilinx, Intel, Lattice, and Microchip FPGAs, and Sital designs the core for DO-254 / DO-178 certifiability up to DAL A. At a glance:

Host interface: memory-mapped AXI4-Lite
Memory mapping: 2 MB at address 0x200000 on the AXI bus
SPI modes: single and dual
Drivers: none required, fully hardware-based
Sourcing: made in the USA, and included free with any Sital SPI card

Top 5 Takeaways

Driverless By Design. The core runs entirely in hardware, so there is no driver stack to maintain and less to certify.
Truly Portable. One vendor-independent VHDL core targets Xilinx, Intel (Altera), Lattice, and Microchip, so changing FPGA families does not force a redesign.
Memory-Mapped Control. You reach SPI directly over AXI4-Lite, with 2 MB mapped at address 0x200000, in both single and dual SPI modes.
Built To Certify. Sital designs the core for DO-254 and DO-178 certifiability, including DAL A.
Sourced With Confidence. The core is proudly made in the USA, and it ships free with any Sital SPI card.

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What Is An AXI To SPI Bridge?

An AXI to SPI bridge connects an FPGA’s internal AXI interconnect to devices that speak the Serial Peripheral Interface (SPI) protocol, the synchronous master–slave serial bus used across most embedded systems. On the AXI side, a processor issues memory-mapped reads and writes. On the SPI side, the bridge turns those reads and writes into clocked serial frames and drives them out to the FPGA pins.

Sital handles that translation in hardware. The core presents a memory-mapped AXI4-Lite interface, maps 2 MB at address 0x200000 on the AXI bus, and drives single or dual SPI with no software driver in the path.

Driverless, Portable, And Vendor-Agnostic

Most FPGA vendors ship an SPI master that depends on software drivers and device-specific configuration. That approach holds up until you change FPGA families. Then the drivers, the FIFO logic, and the integration effort all follow you to the new part. Sital Technology built the AXI to SPI core to end that cycle, and it sits alongside the rest of Sital’s FPGA IP core lineup.

No software drivers: you control the core directly from the AXI bus, in hardware.
One core, four vendor families: vendor-independent VHDL runs on Xilinx, Intel (Altera), Lattice, and Microchip.
Field-tested timing: in a live build on a Xilinx MPSoC running Vivado at a 100 MHz system clock, a recorded single-SPI write cycle finished in about 1.3 µs at 25 MHz, with no software overhead.

Built For High-Reliability Programs

For avionics, aerospace, defense, and space programs, the questions that decide a design are certifiability, reliability, and sourcing. Sital designs the AXI to SPI core for DO-254 and DO-178 certifiability, including DAL A, with certification artifacts available through Sital’s partners. The core pairs with Sital’s SPI cards and drops into existing AXI-based SoC and MPSoC designs. For larger builds, Sital’s Integrated 1553 service handles on-FPGA integration over the AXI bus, end-to-end. Every unit is made in the USA, which keeps programs aligned with ITAR and helps secure the supply chain.

“In our field deployments across FPGA families, the schedule risk that bites teams is rarely the SPI link. It is the driver stack wrapped around it. We made the AXI to SPI core driverless and memory-mapped for exactly that reason, so a team can carry the same validated IP from an Xilinx MPSoC to a Lattice or Microchip part without rewriting a line of low-level software.” — Sital Technology Engineering Team

Essential Resources On “AXI To SPI IP Core For FPGA Designs”

Master The AXI Bus And Memory-Mapped Interfaces

Before you wire up an AXI-to-SPI bridge, it helps to know how AXI4 and AXI4-Lite carry memory-mapped transactions between cores. This engineering paper walks through memory-mapped AXI access in a working FPGA system.

Source: “In-Network Memory Access: Bridging SmartNIC and Host Memory” (arXiv)

See How FPGAs Hold Up In Mission-Critical Applications

NASA’s introduction to FPGA devices lays out the safety, reliability, and security demands of programmable logic in critical systems. Those are the same constraints Sital designs too.

Source: NASA: “Introduction to FPGA Devices and the Challenges for Critical Application”

Understand DO-254 Hardware Design Assurance

The FAA’s best-practices guidance for airborne electronic hardware shows how complex parts like FPGAs earn assurance under DO-254. It even uses an SPI bus as a worked example.

Source: FAA Advisory Circular 00-72: Airborne Electronic Hardware Design Assurance

Know The ITAR Rules For Military Electronics

Category XI of the U.S. Munitions List sets out how military electronics are export-controlled. If you are weighing Made-in-USA sourcing, start here.

Source: eCFR: 22 CFR Part 121, U.S. Munitions List (Military Electronics)

Get The Big Picture On Semiconductor Supply Chains

This Congressional Research Service overview maps the global semiconductor supply chain and where the U.S. sits in it. It is a useful background when you weigh sourcing risk for a long-life program.

Source: Congressional Research Service: “Semiconductors and the Semiconductor Industry”

Track Where Chip Manufacturing Actually Happens

The U.S. International Trade Commission’s briefing on the global semiconductor industry shows how concentrated fabrication has become, and why domestic sourcing matters.

Source: USITC: “Recent Developments in the Global Semiconductor Industry”

Learn Why Authentic, Supported IP Matters

This U.S. Senate inquiry into counterfeit electronic parts in the defense supply chain is a hard look at the cost of unvetted components, and a clear case for supported, traceable IP.

Source: U.S. Senate: Investigation Into Counterfeit Electronic Parts in the DoD Supply Chain

Supporting Statistics

Engineering Demand Is Climbing

The U.S. Bureau of Labor Statistics projects 7% growth in electrical and electronics engineering jobs from 2024 to 2034, faster than the average across all occupations, with roughly 17,500 openings a year. In our experience, that crunch is exactly why teams want IP they can drop in within minutes, not weeks.

Source: U.S. Bureau of Labor Statistics: Electrical and Electronics Engineers, Occupational Outlook Handbook

The Supply Chain Is A Real Risk

When the GAO bought 16 military-grade electronic parts from internet platforms, every one came back suspect counterfeit or bogus, and 334 of the 396 responding vendors sat in China. We have seen the same lesson up close: sourcing discipline is not optional in defense electronics.

Source: U.S. GAO: “Suspect Counterfeit Electronic Parts Can Be Found on Internet Purchasing Platforms”

Domestic Capacity Has Shrunk

America’s share of global chip manufacturing capacity fell from 37% in 1990 to about 10% by 2022, according to the Semiconductor Industry Association. That decline is a big reason Sital keeps its products made in the USA.

Source: Semiconductor Industry Association: “2025 State of the U.S. Semiconductor Industry”

Final Thoughts And Opinion

The AXI to SPI core does one job and does it cleanly. It bridges the AXI bus to single and dual SPI in hardware, with no drivers and no vendor lock-in. That sounds modest. Across the life of a program, it is not.

Here is our view, after years of moving IP across FPGA families. The industry pours effort into driver-based SPI masters and undervalues portability. Drivers are where schedules slip, and certification scope quietly grows, and we have written more about where the real cost of 1553 integration hides. A simple way to weigh it:

If you will only ever ship on one FPGA family and never re-spin, a vendor master may serve you fine.
If you expect to migrate parts, qualify for DAL A, or guard against obsolescence, a driverless, portable, certifiable core is the safer path.

That is the call Sital made with the AXI to SPI core, and it is the one we would make again.

Frequently Asked Questions

Q: What Is The Sital AXI To SPI IP Core?

A: It’s a driverless, memory-mapped bridge that connects an FPGA’s AXI bus to single and dual SPI devices and sends the SPI signals straight to the FPGA pins.

Q: Does It Require Software Drivers?

A: No. The core runs entirely in hardware. You control SPI directly over AXI4-Lite, with no driver stack and no FIFO logic to maintain.

Q: Which FPGAs Does It Support?

A: One vendor-independent VHDL core runs on Xilinx, Intel (Altera), Lattice, and Microchip FPGAs, so changing platforms doesn’t force a redesign.

Q: Does It Support Single And Dual SPI?

A: Yes, both modes, through AXI memory mapping, with 2 MB mapped at address 0x200000 on the AXI bus.

Q: Is It Certifiable For Avionics?

A: Yes. Sital designs it for DO-254 and DO-178 certifiability, including DAL A, with artifacts available through Sital’s partners. It’s made in the USA.

Q: How Do I Get It?

A: The AXI to SPI IP core ships free with any Sital SPI card. Request an evaluation or a quote to get started.

Put A Driverless AXI To SPI Core In Your Next FPGA Design

Drop a portable, driverless AXI-to-SPI bridge into your next FPGA build and leave the vendor lock-in behind. Talk to an expert or request an evaluation to see it run on your platform.

Reliable SPI Connectivity: AXI to SPI IP Core for FPGA Designs