XJTAG® Ultra-Fast Flash Programmer new speed records

Cambridge, United Kingdom. July, 2025 — XJTAG^®, is proud to announce some new speed records set by XJFlash, the ultra-fast in-system flash programmer that uses the JTAG interface to connect to the target board, configuring an on-board FPGA to program a flash device at the maximum supported speed.

In real-world testing with pseudo-random data, a sustained data transfer rate of 32 Mbps was achieved, writing to an Everspin MRAM device. With typical data, even faster speeds are theoretically possible as XJFlash utilises compression on the data transfer algorithm through the JTAG link. This test shows the current top data transfer rate possible with XJFlash, limited by the maximum supported TCK speed of the FPGA because the MRAM device is capable of significantly higher speeds than flash memory. This speed is significantly higher than that supported by flash memory, meaning that XJFlash is limited only by the maximum write speed of the target device.

In further real-world testing, a SPI flash device was programmed at its maximum speed of 12 Mbps, with the following breakdown of overheads and programming time:

FPGA configuration: 2 s
Erase cycle: 0.7 s
Programming 128 Mbit: 10.6 s
Verification: 2.8 s

These stages give a total programming time of 16.1 seconds to fully program and verify a 128 Mbit flash device.

There are a couple of notes behind these numbers. Firstly, with typical (non-pseudo-random) data, the verification stage would complete more quickly as the data can be compressed more before transmission. Secondly, if the device was already programmed, the erase time could be up to 30 seconds in the worst case. Flash devices are unprogrammed when new, so for a production line the lower number is typically more representative.

XJFlash can be used with many FPGAs from AMD (Xilinx), including Versal™, Zynq™ UltraScale+™ and Zynq-7000, as well as with a wide range from Altera (Intel), Lattice, and Microchip (Microsemi, Actel).

Production also benefits from XJFlash’s rapid erase cycle: repaired boards can be processed and tested using exactly the same project. XJFlash checks the existing contents, only erasing blocks it finds aren’t empty — XJFlash can take an empty 128 Mbit flash through the erase step in under 1s, a potential saving of over 90%. That can give very significant time savings over erasing every board passing down the line.

XJFlash can be used as part of an XJRunner boundary scan test project without needing an additional licence, or it can be used for a separate programming-only stage.

To find out more about XJFlash, please visit our website at www.xjtag.com to configure your XJTAG system or to contact us directly.

About XJTAG (www.xjtag.com)

XJTAG is a world leading electronics supplier of testing and programming products and services. The company’s products enable engineers to debug, test, and program electronic circuits quickly and easily. This can significantly shorten the electronic design, development and manufacturing processes. XJTAG focuses on innovative product development and high-quality technical support. For more information about the company, its products and its services, please visit www.xjtag.com.