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Latest revision as of 14:38, 31 August 2026

Introduction

The main function of the Terasic USB Blaster III Download Cable (UBT3) is to allow users to download configuration data to the system during prototype development, or to program data into the system during production. The UBT3 connects the Host and the FPGA on the user's board through the USB Port and 10-Pin cable. At the same time, it can support several target board voltage standards, allowing UBT3 to be widely used in various FPGA boards.

Supported Devices, Host System and Software

The Altera FPGAs, serial configuration device, host systems and Quartus Prime software that UBT3 supported are list in Table 1-1, Table 1-2, Table 1-3 and Table 1-4.

Operating Conditions

UBT3 supports several voltage standard of the target board. Table 1-5 shows the supported voltage. Users need to pay attention to whether the JTAG voltage standard of the target board is within the range of Table 1-5.

Pin Define

The following picture and Table 1-6 list the pins of the Terasic UBT3 Download Cable female plug and describe their functions in the JTAG and Active Serial modes.

LED Description

The LED on the Terasic USB Blaster III download cable indicates different conditions as listed in Table 1-7.

(1) jtagconfig --setparam <cable number> Identify <1=on, 0=off>

Dimension of the Terasic USB Blaster III Download Cable

Using the Terasic USB Blaster III Download Cable

To start using the USB Blaster III Download Cable, user need to install the drivers on your system and set up the hardware in the Altera Quartus® Prime software.

To program or configure the device, connect the host system to the device board using the Terasic USB Blaster III Download Cable and initiate the programming or configuration using the Altera Quartus Prime Programmer. You can also use the cable with the Quartus Prime Signal Tap Logic Analyzer for logic analysis. It also can be used with JTAG and debug tools supported by the JTAG server such as System Console, Nios® V debugger.

• Install the driver for Windows

When installing Quartus Prime software,ensure the following options are selected:

• Install USB Blaster III driver
• Install USB Blaster III driver (Requires UART FTDI driver)
• Install JTAG server as a Windows service and run automatically when Windows starts

• Install the driver for Linux

Altera_USB_Blaster_III_Driver_Installation_Instructions

Changing TCK Frequency of the Terasic USB Blaster III Download Cable

The Terasic USB Blaster III download able has a default TCK frequency of 15 MHz but can be run at 30 MHz if signal integrity and board timing requirements are met.

To change the TCK frequency of the Terasic USB Blaster III download cable, users can use Quartus Prime Programmer and Command Line.

• Changing TCK Frequency with Quartus Prime Programmer

1. In Quartus Prime Programmer, click on Hardware Setup.
2. Under the Hardware Settings tab, uncheck Auto-adjust frequency at chain scanning to disable the feature.
3. Type in one of the recommended frequencies in the Hardware frequency field.
4. Close the Hardware Setup dialog box to save the settings.

• TCK Frequency Auto-Adjust with Quartus Prime Programmer

A checkbox is added in the Quartus Prime Programmer's Hardware Setup dialog box to toggle the auto-adjust frequency feature on and off. When the auto-adjust frequency is enabled, the new adjusted TCK frequency value is shown under the message box of the Programmer GUI. This checkbox is grayed out when the auto-adjust frequency feature is unavailable.

• Changing TCK Frequency with Command Line Programming

To change the TCK frequency of the Terasic USB Blaster III download cable with command line programming:

1. Open the command line interface with the UBT3 bin directory in your path. Example: E:\altera_pro\25.1.1\quartus\bin64
2. Enter the following command to change the TCK frequency: jtagconfig --setparam <cable_number> JtagClock <frequency><unit_prefix>.

cable_number is the UBT3 download able to be modified.

frequency is the desired TCK frequency, it supports 30M,15M,10M,7500K,6M,5M,3M,2M,1M and <30/n>M (between 10kHz and 6MHz, where n represents an integer value number).

unit_prefix is the unit prefix for the frequency (for example, M for MHz)

An example for setting TCK frequency to 6 MHz: jtagconfig --setparam 1 JtagClock 6M

• TCK Frequency Auto-Adjust with Command Line Programming

It is turned on by default and can be toggled on and off via either the command line interface. The feature resets to default when the cable is reconnected or the JTAG server is restarted.

1. To turn off the auto-adjust frequency feature, use the following command: jtagconfig --setparam <cable number> JtagClockAutoAdjust 0
2. To turn on the auto-adjust frequency feature, use the following command: jtagconfig --setparam <cable number> JtagClockAutoAdjust 1
3. You may use the following command to check whether the auto-adjust frequency is enabled. The expected output is 0 if autoadjust is disabled and 1 if the auto-adjust is enabled: Jtagconfig --getparam <cable number> JtagClockAutoAdjust

USB Blaster Self Test

This section describes users how to test whether the on-board USB blaster III or USB blaster III cable is properly installed and operated.

1. Power on the FPGA board and connect USB blaster III port or USB blaster III cable to PC.
   Check if there is JTAG cables in the Windows Device Manager has an USB Blaster III.
   If yes, users can use Quartus programmer and download FPGA code.
   
   
   
2. If USB Blaster III isn’t showed, please check whether the Other devices has Unknown device.
   If yes, please refer to the steps described in this link:Altera USB Blaster II Driver Installation Instructions to install the USB blaster III driver. The installation steps are generic, you just need to select the USB Blaster III driver located in the Quartus installation directory.
   .
   
   
3. If no Unknown device:

i.Make sure the board power is on and the port on board which connected to PC is USB blaster III port.

ii.If step i is OK:

a.Test with another PC to see if the OS can detect unknown device.

b.Test with another USB blaster III cable.

c.If still with the same problem, please contact our technical support team via support@terasic.com and provide below information:

• PC OS version: Win10-64bit, Win11-64bit or Linux-64bit.
• Whether you tested follow the above processes.
• The Quartus version you installed: Quartus Prime 25.1 or others.

FAQ

1. Q: What is the operating temperature specification of the UBT3?

A:The UBT3 is designed to operate in the industrial temperature range (-40°C to +85°C).