it uses a PCIe BUS
Depends, is the device serial or parallel?
parallel
Some key differences between a Serial and Parallel Adder are that a Serial Adder is slower, a Parallel adder is a combinational circuit and the time required for addition depends on the number of bits in a Serial, but not a Parallel. A Serial Adder is a sequential circuit while a Parallel is a combinational circuit.
multiplexer can be used as parallel to serial converter.
Usually serial. Parallel is almost completely gone, and serial is getting replaced by USB.
Serial
A "serial to parallel" converter converts a serial data connection to a parallel data connection. For example, in computer storage, there are controller chipsets that convert SATA (Serial ATA) to PATA (Parallel ATA, also called IDE or EIDE).
parallel
PCIe (PCI Express)
It is less costly to design ever faster serial lines than to create and build the necessary circuitry to keep faster parallel channels properly aligned. This is why Parallel ATA and Parallel SCSI have migrated to Serial ATA (SATA) and Serial SCSI (SAS).
serial chip