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  • Direct programming of SPI flash via J-Link (no CPU / MCU in between)
  • Since J-Link communicates directly with the flash, even flashes connected to CPUs not supported by J-Link can be programmed
  • Cross-platform (command line version for Linux and macOS available)
  • Auto-detection of popular SPI flashes
  • Any SPI flash can be supported. All flash parameters can be manually configured/overridden, if required
  • Can be controlled via command-line
  • Part of the J-Link software and documentation package

J-Flash SPI

J-Flash SPI is a PC software running on Microsoft Windows (backward compatible down to Windows 2000) systems, Linux or macOS, which allows direct programming of SPI flashes via J-Link or Flasher. The flash is programmed directly via J-Link using the SPI protocol, no CPU / MCU in between.

J-Flash SPI

J-Flash SPI is a PC software running on Microsoft Windows (backward compatible down to Windows 2000) systems, Linux or macOS, which allows direct programming of SPI flashes via J-Link or Flasher. The flash is programmed directly via J-Link using the SPI protocol, no CPU / MCU in between.
Most common SPI flashes are automatically recognized by their respective ID and can easily be programmed with no further setup / configuration of J-Flash SPI needed to be done by the user.

Licensing

In order to use J-Flash SPI, either a higher-end J-Link model (J-Link PLUS or higher, click here for the debug probe model overview) or a Flasher Production Programmer (click here for the flash programmer model overview) is needed.

20-Pin Connection

The following table lists the pinout for the SPI interface on J-Link / Flasher.

PinSignalTypeDescription
1 VTrefInputThis is the target reference voltage. It is used to check if the target has power, to create the  logic-level reference for the input comparators and to control the output logic levels to the target. It is normally fed from Vdd of the target board and must not have a series resistor.
2Not connectedNCLeave open on target side.
3Not connectedNCLeave open on target side.
5DIOutputData-input of target SPI. Output of J-Link, used to transmit data to the target SPI.
7 nCSOutputChip-select of target SPI (active LOW).
9CLKOutputSPI clock signal.
11Not connectedNCLeave open on target side.
13DOInputData-out of target SPI. Input of J-Link, used to receive data from the target SPI.
15 nRESETOutputTarget CPU reset signal (active LOW). Typically connected to the reset pin of the target CPU, which is typically called "nRST", "nRESET" or "RESET".
17Not connectedNCLeave open on target side.
195V-SupplyOutputThis pin can be used to supply power to the target hardware. Older J-Links may not be able to supply power on this pin.

Pins 4, 6, 8, 10, 12 are GND pins connected to GND in J-Link. They should also be connected to GND in the target system

*On later J-Link products like the J-link ULTRA, these pins are reserved for firmware extension purposes. They can be left open or connected to GND.

J-Link 10-Pin Needle Adapter Connection

The following table lists the pinout for the SPI interface on J-Link / Flasher when using the J-Link 10-pin Needle Adapter (model 8.06.04).

 

PinSignalTypeDescription
1VTrefInputThis is the target reference voltage. It is used to check if the target has power, to create the  logic-level reference for the input comparators and to control the output logic levels to the target. It is normally fed from Vdd of the target board and must not have a series resistor.
2nCSOutput Chip-select of target SPI (active LOW).
4CLKOutput SPI clock signal.
55V-SupplyOutput This pin can be used to supply power to the target hardware. Older J-Links may not be able to supply power on this pin.
6 DOInputData-out of target SPI. Input of J-Link, used to receive data from the target SPI.
7Not connectedNCLeave open on target side.
8DIOutput Data-input of target SPI. Output of J-Link, used to transmit data to the target SPI.
9Not connectedNCLeave open on target side.
10nRESETOutput Target CPU reset signal. Typically connected to the RESET pin of the target CPU, which is typically called "nRST", "nRESET" or "RESET".

Pin 3 is GND pin connected to GND in J-Link. It should also be connected to GND in the target system.

Notes regarding nRESET:  If there is another device / peripheral that also controls the SPI flash (e.g. a CPU the flash is connected to), nRESET of J-Link should be connected to the reset of the target system or the reset pin of the CPU to make sure that J-Link can keep the CPU in reset while programming the SPI flash.

Which SPI Flash Devices Are Supported?

J-Flash SPI is able to auto-detect common SPI flashes automatically, via their respective ID. Anyhow, since all flash parameters (size, commands etc.) can also be manually configured by the user, any SPI flash device can be supported.

For a list of flash devices that are supported by the flash auto-detection of J-Flash SPI, please refer to here: List of supported SPI flashes

Atmel / Adesto DataFlash

Atmel DataFlash is not supported by J-Flash SPI as its instruction set and handling in general is significantly different from any other SPI flash. Moreover, it's page/sector size is not a power of 2, making is incompatible to existing concepts.

Command Line Version

For Linux and Mac a command line version of J-Flash SPI is available. This command line version is also available under Windows, for users who prefer a command line version over the GUI version (which can also be controlled from commandline). The command line version is also part of the J-Link software and documentation package.

Flash Programming Speed

Due to the high performance and the efficient protocol of J-Link/Flasher, programming speeds up to the max. flash programming specified by the flash vendor, can be achieved.

 

Flash deviceProgramming speed1
ISSI IS25LP128500 KB/s
ISSI IS25LD040100 KB/s
ISSI IS25LQ080340 KB/s
ISSI IS25CD010100 KB/s
ISSI IS25CQ032 190 KB/s
Macronix MX25L3235E285 KB/s
Macronix MX66L1G45G430 KB/s
Macronix MX66L51235F315 KB/s
Micron N25Q128A270 KB/s
Micron M25P10160 KB/s
Micron M25PX16230 KB/s
Micron M45PE10230 KB/s
Micron M25PE4 215 KB/s
Spansion S25FL128410 KB/s
Spansion S25FL116K265 KB/s
Winbond W25Q128FV 340 KB/s

1 Max. flash programming speed that can be achieved depends on flash device. Flash programming is done in pages and page size as well as page programming time varies from device to device. For more information about the page programming time for a specific flash device, please refer to the appropriate datasheet.

FAQs

I have an older version of J-Link. Does it support SPI programming?

A: Please check the SEGGER wiki for more information which J-Link hardware versions support the "SPI interface": wiki.segger.com/Software_and_Hardware_Features_Overview