CH9350L WCH Qinheng USB keyboard and mouse extension control chip

CH9350L is a USB keyboard mouse to serial port communication control chip. With the ease of use of the asynchronous serial port, the USB communication mode between a USB keyboard, mouse, and USB host is extended to an asynchronous serial port (UART), which is convenient for data integration with audio and video signals, or directly extended through the 485 signal 2-wire. It is used for KVM extension, KVM switching, and KM synchronization.

The following is a general application block diagram:

Features:

Supports 12Mbps full-speed USB transmission and 1.5Mbps low-speed USB transmission, compatible with USB V2.0.
The USB port on the upper computer complies with the standard HID protocol, does not require additional driver installation, and supports Windows, Linux, MAC, and other operating systems with built-in HID device drivers.
The same chip can be configured as the upper computer mode and the lower computer mode, respectively connected to the USB-host Host and USB keyboard and mouse.
The same mode can be configured for different working states and is suitable for a variety of applications.
USB keyboard and mouse can be used in the BIOS interface, supports multimedia function keys, and supports USB mice with different resolutions.
Supports various brands of USB keyboard and mouse, USB wireless keyboard and mouse, USB to PS2 cable, USB scanning gun, etc.
The upper and lower computers support hot swap.
Provide send status pin, support 485 communication.
A serial port for 300000/115200/57600/38400 serial communication baud rate.
Built-in crystal oscillator and power-on reset circuit, the peripheral circuit is simple.
Support 5V, 3.3V power supply voltage.
LQFP-48 lead-free package, RoHS compliant.

Applications:

1, applied to KVM extension, more use of working state 1, the state supports more HID device types, multimedia, scanning gun, and other devices;

2, applied to KVM extended + switching, or matrix switching use (multiple pairs of keyboard and mouse on multiple hosts), the use of multiple working state 2, the state supports the use of multiple pairs of different keyboards and mice corresponding to multiple hosts;

3, applied to the mouse screen switching, synchronization, and other functions, the use of working state 3, the state can analyze the serial port data, know the current position of the mouse, detect whether the cursor is on the edge of the screen, so as to achieve the mouse screen switching function;

4, applied to mouse screen switching, synchronization, and other functions, among which some hosts have extended screen, more use the working state 4, the state supports the extended screen function, only part of the system support;

5, used alone, mostly used to convert USB keyboards, mouse, scanning guns, and other devices into serial port data applications, can reduce the development time, do not need to deal with the USB protocol. Use more status 0 or 2 of the lower machine mode;

6, if the data frame length is 64 bytes of the touch screen device, set the baud rate to 300,000;

7, other special applications can be customized for development.