Patent ID: 9501998
Filing Date: 2016-11-22
CPC Classification: G06F,G09G

Claim Text:
1. A display circuit of switchable external display ports, comprising: a graphics display unit, for generating a graphics display signal; a first BIOS, electrically connected to the graphics display unit and storing a first BIOS program code; a second BIOS, electrically connected to the graphics display unit and storing a second BIOS program code; a BIOS switch, electrically connected to the first BIOS and the second BIOS, for enabling one of the first BIOS and the second BIOS and disabling the other, such that the graphics display unit loads only one of the first BIOS program code and the second BIOS program code; an output switch, electrically connected to the graphics display unit; at least one first output port ,electrically connected to the output switch; and at least one second output port, electrically connected to the output switch; wherein the display circuit is arranged such that when the graphics display unit loads the first BIOS program code, the graphics display unit generates the graphics display signal conforming with the first output port, and the output switch is switched to electrically connect the first output port to the graphics display unit to receive the graphics display signal conforming to the first output port; when the graphics display unit loads the second BIOS program code, then the graphics display unit generates the graphics display signal conforming with the second output port, and the output switch is switched to electrically connect the second output port to the graphics display unit to receive the graphics display signal conforming to the second output port; wherein the first output port further includes a detection pin electrically connected to the BIOS switch and the output switch to determine whether the first output port is connected to an external monitor or not, wherein: when the first output port is connected to the external monitor, the detection pin outputs a first switching signal to the BIOS switch and the output switch, and the BIOS switch is switched to enable the first BIOS and simultaneously the output switch is switched to electrically connect the first output port to the graphics display unit; when the second output port is connected to the external monitor, the detection pin outputs a second switching signal to the BIOS switch and the output switch, and the BIOS switch is switched to enable the second BIOS and simultaneously the output switch is switched to electrically connect the second output port to the graphics display unit.