DSJTAG is a 2in1 USB JTAG cable for Xilinx or Altera FPGA/CPLD.

The function of DSJTAG can be toggled by a switch.

When switch down, DSJTAG act as a Xilinx FPGA JTAG, and compatible with Xilinx Platform Cable USB I. (Support all devices and feature)

when switch up, DSJTAG act as a Altera FPGA JTAG, and compatible with Altera USB Blaster. (Support all devices and feature)

DSJTAG will become your friend when you work with FPGA.

DSJTAG will let you never worry about which FPGA should be selected.

You can use DSJTAG with ISE or Quartus, whatever you want.


Function1: Xilinx Platform USB Cable I

1. Compatible with Xilinx Platform USB Cable I, support iMPACT/ISE/Chipscope/EDK  

2. The firmware can be updated by iMPACT, and upgraded to the new version 

3. Atuo detect and adapt the voltage of the target board

4. Support all the xilinx device, include FPGA/CPLD with 5V, 3.3V, 2.5V, 1.8V and 1.5V interface voltage level

5. Support hot-plug at both USB and target side, high impedance when power lose to avoid to damage your target board

6. Tri-color status LED

7. Support programming of SPI FLASH

Function2: Altera USB Blaster

1. Compatible with Altera USB Blaster, support Quartus II/SignalTap II

2. Support all the altera device, include Cyclone III and Stratix II, .etc

3. Support AS/PS/JTAG mode

4. Support communication with Nios II and in-systme debug

5. Bi-color status LED

Application Ideas


The warnings and wrong operations possible cause dangerous.



May include key specification and other specifications.

Pin definition and Rating

Mechanic Dimensions


Function as Xilinx Platform USB Cable I

Found New Hardware Wizard (for Windows only)

Firmware Updates

1. Install Latest IMPACT Software
2. Toggle the switch down, and connect The DSJTAG To The USB Port Of The PC.
3. Open DOS Window And Set The Following Environment Variable To True By Typing The Command On The DOS Prompt:
4. Type, IMPACT On DOS Prompts To Invoke IMPACT Software.
5. When IMPACT Will Open Please Cancel The Project Load Windows And Double Click On The “Boundary Scan” Icon In Flow Window.
6. Select The Source Of The "Platform Cable USB" Cable By Selecting Menu -> “Output” -> Cable Setup -> -> Communication Mode -> Xilinx USB Cable -> And Press OK.
7. IMPACT Software Will Show You The Warning Message “WARNING: IMPACT - Platform Cable USB Firmware Must Be Updated. This Operation May Take Up To 10 Seconds. Please Do Not Stop The Process Or Disconnect The Cable Prior To Completion. The Cable STATUS LED Will Be RED For The Duration Of The Update Process.” Press OK And Wait For The Update To Be Completed.
8. Once The Update Completed, Please “Exit” IMPACT
9. Go To DOS Prompt Windows Which Is Already Open And SET The Environment Variable To False: SET XIL_IMPACT_ENV_USB2_FORCE_CPLD_UPDATE=FALSE
10. Exit The DOS Window By Typing Exit On The Dos Prompt (This Is Very Important).
11. That’s It !! The USB Firmware Is Updated.

Function as Altera USB Blaster

Bill of Materials (BOM) /parts list

Q1,Q2 2N7002/SOT
RN1 33
R2 100K
R3,R4,R5,R6,R7,R8,R9,R10,R14,R16,R19,R20,R21,R22, R23,R24,R26,R27,R29,R30, R31,R35,R36,R37,R39,R41, R42,R45,R46,R47,R48,R50, R51,R72,R73 10K
R17,R62,R67,R70,R71 1K
R18 2K
R28,R33,R34,R58,R59,R64,R68,R69 33
R38,R74 0
R40 18
R43,R44 30K
U1 CY7C68013A-100AXC
U2 XC2C256-7VQ100C
U10 24LC128-I/SN
U11 LM1117-3.3
U12 LM1117-1.8
U15 LM393D
U18 DS2411R
U22,U23,U24,U26 BAT54A
U29 SN74LVC1G126
U35 SRV05-4
U36 74LVC244APW
Y1 24 MHz


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