The controller is a key component for data transfer. The controller is part of transmitting and receiving equipment. The controller is designed for communication with very little delay and with the support QoS (Quality of Service) requests.
One of the many features of QoS is the ability of a network to provide prior information about the bandwidth/delay and according to priority to reserve and manage data flow. Each packet has determined a priority within the packet header called as TLP Header.
Synchronization of clock with the connected device via TB interface will be realized into 8 ns.
TB controller located on the motherboard of PC is always in Host mode (see figure below). The controller includes the independent input for the data from ports PCI-E and DP. PCI-E controller (PCI-E Switch) is inside TB controller which controls the connected terminal device and NHI (Native Host Interface) element, which is used for detection of the connected device (support Plug&Play). The last element is a Thunderbolt Switch, which combines both types of data into a single data stream.
One TB port requires two channels. Each consists of two paths for bidirectional transmission and it has a channel capacity of 10 Gbit/s. One channel is used for image data and another for other data. Because the performance of TB interface is not given as sum of performance of each channels, the official mentioned throughput is of 10 Gbit/s per port. Thus the controller has four outputs according to given solution.
TB controller for terminal equipments connected to the PC is in terminal mode (Endpoint). There are available four inputs respectively outputs according to the type of operation. Received data come into the Thunderbolt switch, which is a very powerful protocol switch. Data is distributed in it according to their protocol. Data of DP port get off from the controller (DP out) and data of PCI-E bus come into the PCI-E switch. Then it divides the data according to the specifications of the 4-channel PCI-E 2.0. It is possible to connect one (4-channel), two (2-channel) or four (1-channel) equipments. PCI-E switch, which is located in front of the equipment, controls data routing in serial connection of more devices. Each element connected in the serial connection must include two ports. If it contains only one port, it is unable to transfer data to other devices and is therefore connected to the chain end. Typical example is a monitor. The device has the smallest delay, when it is in topology diagram in the first place. The data are subsequently divided and come into microchip PCH (Platform Controller Hub), which determines the data path and controls the auxiliary function in cooperation with a CPU (Central Processing Unit) (e.g. the system clock) and the memory. The connection between the controller and the PCH includes FDI (Flexible Display Interface) interface that realize a separate band for transferring of image data.
When applying fiber optic technology it won’t be necessary to change the current devices with TB interface. These devices are already capable of transmitting data over both copper and fiber optic cables. The cables may have in the case of the optics reachable range up to several tens of meters while power using metallic conductors. Without the need to the power supply of the remote device is calculated with the transmission of the optical signal up to hundreds of meters.