217 - GL3224 Card Reader: Understanding and Design Case

Video Links:
Bilibili Video -- Production Process and Design Interpretation
Project Introduction
First, here are the projects I referenced:
https://oshwhub.com/scarrr0725/gl3224
https://oshwhub.com/Axin/3-0-du-ka-qi-ji-yu-gl3224-zhi-chi-xiang-ji-sd-ka
https://oshwhub.com/shadow27/ji-yu-gl3224-di-usb3-0-du-ka-qi
My QQ groups: 874577320, 232586710, 345731137
This card reader based on the GL3224-32PIN version
absorbs and draws inspiration from various open-source projects, supplementing and sharing my own test data and design considerations.
Project Functionality and Performance Testing
TF card read/write function, can be read and written by directly connecting to the computer via USB-A male connector.
Performance test chart: (Test date: October 17, 2024, afternoon) ( Using an unknown 64G memory card)
The image above shows the device before firmware upgrade.
The image above shows the device after firmware upgrade. However, this test is incomplete, with insufficient number of tests and is for reference only!
Actual testing shows support for 128G SD cards (in other designs, the same chip and peripherals are used).
Project parameters
: The main controller is GL3224, QFN32 version. The QFN48 version is not discussed here, but the latter should have the ability to read and write to two cards simultaneously.
Principle analysis (hardware description):
Connect the chips directly according to the chip block diagram and various open-source materials.
Chip input terminals: two PHYs, one USB2, one USB3@5Gbps.
Regarding firmware
: After incomplete testing, the chip's built-in 1532 firmware is not inferior to the 1536 in performance. The physical transmission of USB3 is not a problem. However, I have still included the firmware tool in the attachment. The firmware tool's config.ini also provides more supported memory chips not mentioned in the official documentation.
Basic requirements for memory chips: The memory chip used must have at least 512Kbit
. The upgrade tool is shown in the image below. After soldering, power on and open the software. Click "start" to upgrade.
Notes:
REXT currently has two available values: 680R (official datasheet recommends 680R) and 1K (also available). I recommend the former.
When replicating, it's suggested to place capacitors close to the chip pins, ideally on the back of the chip, to facilitate signal and power separation.
It's also recommended to ground the crystal oscillator to reduce interference with the USB3 differential pair.
The capacitor reserved for the crystal oscillator varies depending on the actual crystal being soldered, typically around 10-20pF.
If one side is close to 0V and the other is 3.3V, the crystal oscillator is definitely not functioning correctly!
Actual testing shows it generates considerable heat during operation. It's recommended to use a DC-DC independent power supply for the TF card during replication. Most TF cards can withstand 3-4.2V input (don't try 5V).
Write protection is disabled by grounding the pin on the toggle switch. This pin has an internal pull-up, so leaving this pin floating enables write protection. (
Image of actual product)