CBTL04DP211 is an (Embedded) DisplayPort multiplexer for DisplayPort v1.1a switching
and multiplexing applications on PC platforms. It is capable of 1 : 2 switching or
2 : 1 multiplexing of 2-lane DisplayPort Main Link signals, using high-bandwidth pass-gate
technology. Also, it can switch/multiplex Hot Plug Detect (HPD) signal and AUX signals,
for a total of four channels on the display side.
To facilitate DisplayPort switching/multiplexing scheme on PC platforms suitably,
CBTL04DP211 provides two separate selection pins (GPU_SEL, AUX_SEL). The
selection pin GPU_SEL performs switching from one Main Link to another Main Link. HPD
signals will also be switched using the same selection pin. A separate select pin
(AUX_SEL) provides additional selection between two AUX channels such that the AUX
channel selection is independent of the Main Link and HPD signal selection.
A typical application of CBTL04DP211 is on motherboards where one of two GPU/CPU
display sources needs to be selected to connect to a DisplayPort sink device or connector.
A controller chip selects which path to use by setting a select signal HIGH or LOW. Due to
the non-directional nature of the signal paths (which use high-bandwidth pass-gate
technology), the CBTL04DP211 can also be used in the reverse topology, e.g., to connect
one DisplayPort source device to one of two DisplayPort sink devices or connectors.