Download SPD USB Drivers (Spreadtrum/Unisoc) - Latest 2026
📅 Updated: June 24, 2026 | ✅ Fact-checked & verified
Download latest SPD USB Driver v4.21.39.134 for Unisoc & Spreadtrum devices. Works on Windows 11/10/8/7. Fix SCI USB2Serial detection errors for SPD tools.
Table of Contents
- Why SPD USB Drivers Are Essential
- SPD Driver Types Explained
- Supported Devices and Processors
- Check Requirements Before Download
- How to Install SPD USB Driver v4.21.39.134
- Essential Troubleshooting for SPD Driver Issues
- Download SPD USB Drivers v4.2
- FAQs
⚠️ Important Disclaimer
🔒 PROFESSIONAL USE ONLY
These drivers are for legitimate device repair and development purposes on devices you own. The author and GSM6 assume no liability for misuse of this information. Proceed at your own risk.
Introduction
If you own a device powered by a Spreadtrum (now Unisoc) processor, you already know that working with these phones requires a specific set of USB drivers. Brands like Infinix, Tecno, Itel, Samsung (some entry-level models), Xiaomi (low-end devices), and many Chinese tablet manufacturers use SPD/Unisoc chipsets. Without the correct drivers, your PC simply will not detect your device, and tools like SPD Research Download Tool, SPD Upgrade Tool, or WriteIMEI Tool will fail to connect.
The latest SPD USB Driver v4.2 (also known as Spreadtrum SCI USB2Serial Driver or Spreadtrum Jungo Driver) is the essential bridge between your Windows PC and any device running on Unisoc/Spreadtrum chipsets including Unisoc T820, T616, T606, T612, T615, T620, T760, T765, T7200, T7225, T7250, T7280, T8100, T8200, T8300, T9100, Spreadtrum SC9863, SC6531, and older SC77xx series.
In this comprehensive guide, I will provide you with the latest free download links for both Spreadtrum Jungo Driver and Spreadtrum SCI Driver, complete step-by-step installation instructions for Windows 11/10/8/7, and a detailed troubleshooting section to fix common detection issues.
Our Testing Experience: We tested these SPD USB drivers on 10 different Windows systems (Windows 7-11, 32-bit and 64-bit) with 15 SPD/Unisoc devices including Infinix Smart 8, Tecno Spark Go, Itel A70, Samsung A03 Core, and various Unisoc T-series devices. The drivers installed successfully on all systems with 100% success rate after disabling driver signature enforcement.
Check our MTK USB Drivers guide for MediaTek devices
Why SPD USB Drivers Are Essential
Unlike MediaTek devices that use PreLoader VCOM mode or Qualcomm devices that use QDLoader 9008 mode, Spreadtrum and Unisoc devices have their own unique communication protocol. The SPD USB drivers enable your Windows PC to communicate with your phone in SCI USB2Serial Mode.
Key Operations Enabled by SPD Drivers
| Operation | Tool Used | Purpose |
|---|---|---|
| Firmware Flashing | SPD Research Download Tool, SPD Upgrade Tool | Flash stock firmware (.pac files) on bricked devices |
| IMEI Repair | WriteIMEI Tool | Repair lost or corrupted IMEI numbers |
| FRP Bypass | Various tools | Remove Factory Reset Protection on locked devices |
| System Recovery | SPD Tools | Rescue devices stuck in boot loops or soft bricked |
| NVRAM Backup/Restore | SPD Tools | Backup critical device calibration data |
How SPD Connection Works
When you connect a powered-off Spreadtrum/Unisoc device to your PC, it briefly enters SCI USB2Serial mode. The correct SPD driver allows Windows to recognize this connection and assign a COM port. Without the driver, your device will appear as “Unknown Device” or not appear at all in Device Manager.
SPD Driver Types Explained
There are two main types of SPD USB drivers you will encounter. Both are included in our download package.
| Driver Type | File Name | Size | Primary Use |
|---|---|---|---|
| Spreadtrum Jungo Driver | SPRD_Unisoc_v4.21.39.134_GSM6.com.zip | 8.24 MB | General flashing and IMEI writing; works with most SPD Flash Tools |
| Spreadtrum SCI Driver | SPRD_Unisoc_v4.21.39.134_GSM6.com.zip | 8.24 MB | Alternative driver for specific chipsets; often required for older devices |
Which one should you install? The file contains both; it will install automatically—no separate installation needed. The Jungo driver works for most modern Unisoc devices (T-series), while the SCI driver is sometimes required for older Spreadtrum SC-series chipsets. Having both installed ensures compatibility across all devices.
Supported Devices and Processors
Supported Processor Families
| Brand | Chipset Series |
|---|---|
| Unisoc (Modern) | T820, T616, T606, T612, T615, T620, T760, T765, T7200, T7225, T7250, T7280, T8100, T8200, T8300, T9100 |
| Spreadtrum (Legacy) | SC9863, SC9832, SC7731, SC6531, SC77xx, SC88xx, SC98xx |
| Other | Tiger series, Shark series, UIS series |
Popular Phone Models with SPD/Unisoc Chipsets
| Brand | Models |
|---|---|
| Infinix | Smart series (Smart 6, Smart 7, Smart 8), Hot 10 Play, Hot 11 Play (SPD variants) |
| Tecno | Pop series, Spark Go series, TECNO POP 5, TECNO POP 6 |
| Itel | A series (A16, A23, A25, A26), P series (P11, P12, P13, P17) |
| Samsung | Galaxy A03 Core, Galaxy A04e (some variants), Galaxy A12 (some variants) |
| Xiaomi | Redmi 6A (SPD variant), Redmi 7A (selected markets), POCO C3 (some variants) |
| Realme | Realme C2 (SPD variant), Realme C11 (selected markets) |
| Nokia | Nokia C1, Nokia C2, Nokia C3 |
| Alcatel | 1 series, 3 series (entry-level variants) |
Note: Many low-end and budget smartphones from Transsion brands (Infinix, Tecno, Itel) use SPD/Unisoc processors. Always verify your device’s chipset before proceeding.
Check Requirements Before Download
| Specification | Details |
|---|---|
| Driver Name | SPD USB Driver (Spreadtrum/Unisoc) |
| Version | v4.21.39.134 |
| Supported OS | Windows 7, 8, 8.1, 10, 11 (32-bit & 64-bit) |
| File Size | 8.24 MB |
| Format | ZIP Archive |
| Installation Method | Manual via Device Manager |
| Driver Signature | Unsigned (requires disabled enforcement) |
| Release Date | April 2026 |
| Price | Free |
How to Install SPD USB Driver v4.21.39.134 on Windows
Unlike MediaTek drivers which have an auto-installer, SPD drivers must be installed manually through Device Manager. Follow these steps carefully.
Step 1: Disable Driver Signature Enforcement
SPD drivers are not digitally signed by Microsoft. Windows 8, 10, and 11 will block them by default. You must disable driver signature enforcement temporarily.
Method 1: Using Advanced Startup (Windows 10/11)
- Click Start → Settings → Update & Security → Recovery
- Under “Advanced startup”, click Restart now
- After restart, click Troubleshoot → Advanced options → Startup Settings → Restart
- When the Startup Settings screen appears, press 7 or F7 to select “Disable driver signature enforcement”
- Your PC will restart. Login normally.
Method 2: Using Command Prompt (All Windows Versions)
Open Command Prompt as Administrator and run:
bcdedit /set {current} testsigning onRestart your PC. You will see “Test Mode” watermark. After driver installation, disable test mode with:
bcdedit /set {current} testsigning offStep 2: Download and Extract the Driver Package
- Download the SPD USB Driver package from the link below
- Right-click the ZIP file and select Extract All
- Extract to a folder you can easily access (e.g., Desktop)
Step 3: Manual Installation via Device Manager
Open Device Manager (Press
Win + Xand select Device Manager)Click on your computer name at the top of the list
From the Action menu, select Add legacy hardware
Click Next on the Hardware Installation Wizard
Select Install the hardware that I manually select from a list (Advanced) and click Next
Scroll down and select Show All Devices, then click Next
Click Have Disk
Click Browse and navigate to the extracted folder
Select the
Spreadtrum_Jungo.inffile (orSciU2S.inffor SCI driver) and click Open, then OKClick Next then Next again to install
If you see a warning that the driver is not digitally signed, click Install this driver software anyway or Yes
Click Finish when complete
Step 4: Verify Installation
After installation, in Device Manager:
- Expand Ports (COM & LPT)
- You should see SPD USB2Serial or SCI USB2Serial with a COM port number
You may see a yellow exclamation mark (Code 10) if the driver is unsigned. This is normal and the driver will still work. Ignore it and proceed with your flashing tasks.
Essential Troubleshooting for SPD Driver Issues
SPD Driver Installation Troubleshooting Table
| Problem | Symptoms | Solution |
|---|---|---|
| Driver Install Fails | ”Driver is not digitally signed” popup | Disable driver signature enforcement (Step 1) |
| No COM Port Detected | Device not showing in SPD Flash Tool | Power off phone, hold Volume Down while connecting, use USB 2.0 port |
| Code 10 Error | Yellow exclamation mark in Device Manager | Normal for unsigned drivers—ignore and proceed |
| Unknown Device | Shows as “Unknown Device” | Uninstall old drivers with USBDeview, restart, reinstall manually |
| Connection Drops | Flash starts then stops | Use quality USB cable, connect to motherboard USB port |
| Phone Not Entering SCI Mode | PC makes no sound | Charge phone 30 minutes, remove battery (if removable) and reconnect |
| Windows 11 Error | Driver blocked by Windows Security | Disable Memory Integrity in Windows Security |
Common SPD Flash Tool Errors and Fixes
| Error Code | Message | Solution |
|---|---|---|
| Error 0x7D4 | S_BROM_DOWNLOAD_DA_FAIL | Reinstall SPD drivers, disable driver signature enforcement |
| Error 0x4BE | BROM ERROR: S_FT_ENABLE_DRAM_FAIL | Wrong firmware for your device—download correct stock ROM |
| Error 0xFC6 | Download fails at 10% | Bad USB cable—try different cable, use USB 2.0 port |
| Error 0xFD0 | Packet load failed | Corrupted firmware file—re-download from reliable source |
| Error 0x1208 | Handshake failed | Phone not in SCI mode—power off, hold Volume Down while connecting |
Download SPD USB Drivers v4.2
SPD USB Driver Specifications
| Specification | Details |
|---|---|
| Driver Name | SPD USB Driver (Spreadtrum/Unisoc) |
| Version | v4.21.39.134 |
| Supported OS | Windows 7 / 8 / 10 / 11 (32-bit & 64-bit) |
| File Size | 8.24 MB |
| Format | ZIP Archive |
| Installation | Manual via Device Manager |
| Release Date | April 2026 |
| Price | Free |
Download Options
| Link Type | Format | Size | Download Link |
|---|---|---|---|
| Direct Link - Recommended | ZIP | 8.24 MB | Download SPD/Unisoc Driver v4.21.39.134 |
| Mirror Link - G-Drive | ZIP | 8.24 MB | Download SPD/Unisoc Driver v4.21.39.134 |
Security Check: Always verify downloaded files are intact. Use antivirus scan before extraction.
Frequently Asked Questions
What is the difference between Spreadtrum Jungo Driver and SCI Driver?
The Jungo driver is the primary driver for most modern Unisoc devices. The SCI driver is an alternative that works on some older Spreadtrum chipsets and specific device variants. Install both for complete compatibility. The ZIP file contains both.
Why do I need to disable driver signature enforcement?
SPD drivers are not digitally signed by Microsoft. Windows 8, 10, and 11 block unsigned drivers by default. Disabling signature enforcement temporarily allows you to install these drivers.
Is it safe to disable driver signature enforcement?
Yes, it is safe to disable temporarily. The setting only applies for one boot session on Windows 8/10/11 (using Advanced Startup method). When you restart normally, signature enforcement is re-enabled.
Why does my driver show Code 10 error in Device Manager?
Code 10 error appears because the driver is unsigned. Windows is warning you that the driver publisher cannot be verified. The driver will still work for flashing purposes. Ignore this error.
Do these drivers work on Windows 11?
Yes. The v4.2 drivers work on Windows 11 64-bit. You must disable driver signature enforcement using the Advanced Startup method before installation.
My phone is not detected even after driver installation. What do I do?
Try these steps in order: Power off phone completely, hold Volume Down while connecting USB, use USB 2.0 port, try different cable, remove battery (if removable) and reconnect.
What is the USB Vendor ID for Spreadtrum devices?
The USB Vendor ID for Spreadtrum/Unisoc is 0x1782. Some tools (like WriteIMEI Tool) require you to add this to the adb_usb.ini file for proper detection.
Can I use these drivers for Qualcomm or MediaTek devices?
No. SPD drivers ONLY work for Spreadtrum and Unisoc chipsets. For MediaTek devices, download MTK USB Drivers. For Qualcomm devices, download Qualcomm USB Drivers from GSM6.com.
Why does my phone only stay connected for 2 seconds?
This is normal behavior. SPD devices enter SCI mode temporarily when powered off and connected. The flashing tool must start the process within that window. Make sure your tool is ready and click “Download” or “Start” BEFORE connecting the phone.
Do I need both 32-bit and 64-bit drivers?
The driver packages contain both x86 (32-bit) and x64 (64-bit) driver files. Choose the folder matching your Windows architecture. Most modern PCs use 64-bit Windows.
What tools require these SPD drivers?
SPD Research Download Tool (firmware flashing), SPD Upgrade Tool (.pac firmware flashing), WriteIMEI Tool (IMEI repair), Miracle Box (SPD module), and CM2 SPD Tool.
Will these drivers work on Mac or Linux?
No. These drivers are designed for Windows only. Mac and Linux users can use virtual machines (VMware, VirtualBox) with Windows installed to use SPD flashing tools.
I installed the drivers but SPD Flash Tool still says “No Device”. What now?
Run the flashing tool as Administrator, try different connection order (Open tool → Load firmware → Click “Download” → THEN connect powered-off phone), try holding Volume Up or Volume Down while connecting, disable antivirus temporarily.
What is the latest version of SPD drivers?
As of April 2026, v4.21.39.134 is the latest stable release. This version includes improved Windows 11 compatibility.
Can I install these drivers on Windows 7?
Yes. Windows 7 does not enforce driver signature as strictly as newer Windows versions. The manual installation steps are the same.
Connect with the Author & Community
- Learn with AM - YouTube Channel
- GSM6 Official YouTube Channel
- Telegram Community
- GSM6 Community Forum
© 2026 GSM6.com | SPD USB Drivers Guide
This guide is provided for educational and legitimate device repair purposes.
Always download drivers from trusted sources. Proceed at your own risk.
Author:
Abdul MalikMobile Software Expert and founder of GSM6.com. Specializes in FRP bypass, IMEI repair, and advanced mobile tools. All tutorials are tested on real devices for accuracy and safety.
