Usb Features - Dell Vostro 3681 Service Manual

Figure 3. Curved edge
Memory Errors
Memory errors on the system display 2,3 failure code. If all memory fails, the LCD does not turn on. Troubleshoot for possible memory
failure by trying known good memory modules in the memory connectors on the bottom of the system or under the keyboard, as in some
portable systems.
NOTE: The DDR4 memory is imbedded in board and not a replaceable DIMM as shown and referred.

USB features

Universal Serial Bus, or USB, was introduced in 1996. It dramatically simplified the connection between host computers and peripheral
devices like mice, keyboards, external drivers, and printers.
Table 1. USB evolution
Type Data Transfer Rate
USB 2.0 480 Mbps
USB 3.2 Gen 1 5 Gbps
USB 3.2 Gen 1 (SuperSpeed USB)
For years, the USB 2.0 has been firmly entrenched as the de facto interface standard in the PC world with about 6 billion devices sold, and
yet the need for more speed grows by ever faster computing hardware and ever greater bandwidth demands. The USB 3.1 Gen 2 finally
has the answer to the consumers' demands with a theoretically 10 times faster than its predecessor. In a nutshell, USB 3.2 Gen 1 features
are as follows:
• Higher transfer rates (up to 5 Gbps)
• Increased maximum bus power and increased device current draw to better accommodate power-hungry devices
• New power management features
• Full-duplex data transfers and support for new transfer types
• Backward USB 2.0 compatibility
• New connectors and cable
The topics below cover some of the most commonly asked questions regarding USB 3.2 Gen 1.
Speed
Currently, there are 3 speed modes defined by the latest USB 3.2 Gen 1/USB 3.2 Gen 1 and USB 3.2 Gen 2x2 specification. They are
Super-Speed, Hi-Speed and Full-Speed. The new SuperSpeed mode has a transfer rate of 4.8 Gbps. While the specification retains Hi-
Speed, and Full-Speed USB mode, commonly known as USB 2.0 and 1.1 respectively, the slower modes still operate at 480 Mbps and 12
Mbps respectively and are kept to maintain backward compatibility.
USB 3.2 Gen 1 achieves the much higher performance by the technical changes below:
10 Technology and components
Category
High Speed
SuperSpeed
Introduction Year
2000
2010