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USB1.1 and USB2.0
- Apr 25, 2018 -

USB1.1 is a relatively common specification of USB. Its high-speed transmission rate is 12Mbps,low-speed transmission rate is 1.5Mbps (b means bit), and 1MB/s (megabytes/second) = 8MBPS (megabits). /s), 12Mbps = 1.5MB/s. Currently, most MP3s are such interface types.

The USB2.0 specification evolved from the USB1.1 specification. Its transmission rate has reached 480Mbps, converted to MB is 60MB/s, enough to meet the speed requirements of most peripherals. The Enhanced Host Controller Interface (EHCI) in USB 2.0 defines an architecture that is compatible with USB 1.1. It can drive USB 1.1 devices with USB 2.0 drivers. In other words, all USB 1.1-capable devices can be used directly on the USB 2.0 interface without worry about compatibility issues, and accessories such as USB cables, plugs, etc., can also be used directly.

The change brought by the use of USB for printer applications is a significant increase in speed. The USB interface provides a connection speed of 12 Mbps, which is more than 10 times faster than the parallel port speed, at which speed the print file transfer time is greatly reduced. The USB 2.0 standard further increases the speed of the interface to 480Mbps, which is 20 times of ordinary USB, greatly reducing the transmission time of the print file.

USB is a commonly used PC interface, it only has 4 lines, two power and two signals, so the signal is transmitted serially. USB interface is also known as the serial port. The speed of USB 2.0 can reach 480Mbps and can meet a variety of industrial and civilian needs.

The output voltage and current of USB interface is: +5V 500mA (actually has error, the maximum can't exceed +/-0.2V that is 4.8-5.2V)

The four lines of the USB interface are generally assigned as follows: black line: gnd red line: vcc green line: data+ white line: data