This document describes the Xbox controller as a USB device. Readers are expected to have working knowledge on USB 1.1 and USB HID class.
Throughout this document, the term “controller” refers to the whole controller product and “gamepad” refers to the gamepad portion thereof (excluding the integrated hub and the memory unit slots).
Overview
The Xbox controller is in brief a USB compound device that consists of a USB gamepad and a two-port USB hub. The hub internally has three ports, to one of which the gamepad is attached. The other two ports are the memory unit slots; it means the memory unit is also a USB device (mass storage class). The USB cable and the memory unit connector carries five signals, four of which are standard USB signals and the rest is a clock signal(?). The extra signal is not used by the gamepad and the memory unit; it seems to be provided for upcoming expansion devices.
You can connect the controller to a PC by ripping the cable and soldering a USB connector. However, the controller does not work either with the generic USB joystick driver or with the generic mass storage driver, because the interface class/subclass values are strange, the HID descriptor and the HID report descriptor are missing, and so on.
USB Device Model
Here are descriptor dumps of the hub, the gamepad and the memory unit.
- Descriptors of the integrated hub
- Descriptors of the gamepad (American)
- Descriptors of the memory unit
Vendor / Product IDs
The vendor ID is 0x045e (Microsoft). Product IDs are as follows:
| ID | product |
|---|---|
| 0x001c | integrated hub |
| 0x0202 | gamepad (American) |
| 0x0280 | memory unit |
| 0x0284 | DVD remote receiver |
| 0x0285 | gamepad (Japanese) |
It is not recommended to distinguish Xbox gamepads by vendor/product IDs because third-party controllers may have their own vendor/product IDs.
Device Class
The gamepad has interface class 0x58 (‘X’), subclass 0x42 (‘B’), protocol 0x00. I believe this should be also common to third-party controllers, but I have no evidence. In fact the gamepad conforms to the HID class and behaves like a USB HID gamepad except that it lacks the HID descriptor and the HID report descriptor.
The memory unit has interface class 0x08 (mass storage), subclass 0x42 (‘B’=???), protocol 0x50 (bulk-only). It seems to conform to the mass storage device class with bulk-only transport, though the “true” subclass must be revealed to access the unit.
HID Report Format
The input report is 20-byte.
| offset | data | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| +0 | 0x00 | ||||||||||||||||
| +1 | 0x14 (size of the whole report) | ||||||||||||||||
| +2 | digital buttons
|
||||||||||||||||
| +3 | 0x00 (reserved for more digital buttons?) | ||||||||||||||||
| +4 | A button (*) | ||||||||||||||||
| +5 | B button (*) | ||||||||||||||||
| +6 | X button (*) | ||||||||||||||||
| +7 | Y button (*) | ||||||||||||||||
| +8 | black button (*) | ||||||||||||||||
| +9 | white button (*) | ||||||||||||||||
| +10 | L trigger (*) | ||||||||||||||||
| +11 | R trigger (*) | ||||||||||||||||
| +12 | left stick x (**) | ||||||||||||||||
| +14 | left stick y (**) | ||||||||||||||||
| +16 | right stick x (**) | ||||||||||||||||
| +18 | right stick y (**) |
- (*) unsigned 8-bit
- (**) signed 16-bit, little-endian, north/east positive
Output Report
The output report (rumble control) is 6-byte.
| offset | data |
|---|---|
| +0 | 0x00 |
| +1 | 0x06 (size of the whole report) |
| +2 | 0x00 |
| +3 | left actuator (*) |
| +4 | 0x00 |
| +5 | right actuator (*) |
(*) unsigned 8-bit
Example of the HID Report Descriptor
The Xbox gamepad lacks the HID report descriptor that describes the input/output report formats. Based on the above report formats I have tried writing the report descriptor for your information. This is a mere example; neither official nor verified. Accuracy is not guaranteed.
- Text format
- Binary format
- HID Descriptor Tool format (to be loaded into HID Descriptor Tool)
*For convenience, the text files have been included with the XBCD driver on the download page.
This page is an archive of the original post found here.
