D60 Upscaling Fuser Guide

The Dichen D60 4K Fuser (aka Dichen p1) allows a Main PC (DisplayPort 1.4) and an Overlay PC (HDMI 2.1) to feed separate signals that are fused together. This guide covers some resolution tips, firmware upgrades and other stuff

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1. System Overview

Inputs:

• Main PC → DisplayPort 1.4
• Overlay PC → HDMI 2.1

Output:

• Combined fused signal to your display.

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2. Supported Resolutions & Refresh Rates

The D60 supports high refresh rates on the main DP 1.4 input. Some combinations may only be possible at 6 bits per color (6 bpc) due to DP 1.4 bandwidth limits.

Resolution / Refresh (Main)	Notes
3840×2160 @ 120 Hz (4K120)	May require 6 bpc or DSC
2560×1440 @ 240 Hz (QHD240)	May require 6 bpc
1920×1080 @ 360 Hz (1080p360)	May require 6 bpc

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3. Overlay Resolution Rules

• Overlay HDMI resolution should ideally be exactly half the main PC resolution in each dimension for perfect 2:1 scaling.
• Examples:
  • Main: 3840×2160 → Overlay: 1920×1080
  • Main: 2560×1440 → Overlay: 1280×720
  • Main: 1920×1080 → Overlay: 960×540 (or 1280×720 for convenience)
• The D60 upscales the overlay to match the main resolution.

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4. HDMI 2.1 Requirement (Overlay)

The overlay input must be HDMI 2.1.

• Many mini PCs only have HDMI 2.0 on Intel iGPUs — these are not sufficient.
• Use a discrete NVIDIA or AMD GPU to ensure HDMI 2.1 support.
• If you must use Intel, a true HDMI 2.1 adapter is required (verify FRL support).

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5. Setting Resolutions

Windows Settings (Main PC)

1. Settings → System → Display → Advanced display
2. Select the D60 output.
3. Set desired resolution and refresh rate.

NVIDIA Control Panel

1. Right-click desktop → NVIDIA Control Panel.
2. Change resolution → Select D60 output.
3. Adjust color format, color depth (try 6 bpc if needed), and refresh rate.
4. Use Custom Resolution if mode is missing.

AMD Software

1. Open AMD Software → Settings → Display.
2. Create custom resolutions if needed.
3. Adjust Pixel Format and Color Depth.

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6. Bandwidth & Stability Tips

• Use short, certified DP 1.4 and HDMI 2.1 cables.
• If a mode fails:
  1. Lower bit depth (6 bpc if possible)
  2. Reduce chroma (YCbCr 4:2:2 or 4:2:0)
  3. Disable HDR
  4. Enable DSC if supported

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7. Firmware Upgrade — Dichen 4K Fuser (D60)

⚠️ Important: Only upgrade with the official package from Dichen to avoid bricking your device (check releases in this repo) Also do this on your overlay PC

Step 1 — Enter Upgrade Mode

1. Connect D60 to power and the USB-C port on your PC.
2. Hold the power button on the back and the small button under “D60” on the front at the same time.
3. The lower-left indicator light will stay red — this means you’re in upgrade mode.

Step 2 — Prepare the Upgrade Package

• Download the correct BIN firmware file from official sources.
• Keep it in an accessible location on your PC.

Step 3 — Load the Firmware

1. Open the official Dichen firmware tool.
2. Select the correct COM port (e.g., COM3 in Windows Device Manager).
3. Set file type to BIN.
4. Click the ... button, browse to the firmware file, and select Open.

Step 4 — Send the Firmware

1. Click Send in the firmware tool.
2. The D60 indicator will turn green during transfer.
3. Wait until you see "Send Complete" in the status bar.
4. Do not disconnect power during the process.

Step 5 — Finish

1. Power off the D60 after completion.
2. Firmware upgrade is done.

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8. Quick Checklist

• Main PC on DP 1.4
• Overlay PC on HDMI 2.1
• Overlay resolution = half of main
• Use 6 bpc for high-refresh stability
• Use certified cables

Other info

Parts List

Core Processing

• Xilinx Kintex-7 FPGA
  • Part: XC7K325T-2FBG676C
  • Role: Primary logic for video fusion, EDID manipulation, and timing alignment.

Memory

• DDR3 SDRAM
  • Quantity: 4x ICs
  • Role: Framebuffer and temporary storage for FPGA operation.

Display Control MCU

• STMicroelectronics STM32F103C8T6
  • Core: ARM Cortex-M3
  • Flash: 64 KB
  • RAM: 20 KB
  • Role: OSD display rendering, serial communication with EDID.exe, firmware update interface.

USB-to-Serial Bridge

• WCH CH340C
  • Role: USB-to-UART interface for .bin file injection via EDID.exe.

Video Signal Integrity

• Texas Instruments DP141
  • Function: HDMI redriver / signal conditioner for TMDS integrity between HDMI ports and FPGA.

Non-Volatile Storage

• SPI NOR Flash (i think Winbond W25Q64)
  • Capacity: 8 MB
  • Role: Bitstream storage for FPGA, configuration data, and possibly overlay font tables.

Voltage Regulation

Voltage Rail	Purpose
3.3V	IO for MCU, SPI flash, HDMI PHY
2.5V	DDR3 I/O
1.8V	Core voltage for logic level shifters
1.2V	DDR3 core, FPGA auxiliary supply
0.95V	FPGA VCCINT core voltage

Connectors

• HDMI Inputs and Outputs

  • Ports: 1 dp input, 1 hdmi input, 1 dp output
  • Routed directly into FPGA through DP141 redrivers.

• USB-C Port

  • Function: Serial data interface via CH340C (not for power).

  • Pins: 4-pin header, located adjacent to the STM32F103 microcontroller (between the MCU and the USB-C port)

  • Role: Debug and firmware flashing via ST-Link or CMSIS-DAP.