Transceiver and loopback test method for transceiver

A transceiver comprising:

• a first receiver pad configured to receive a first external voltage;
• a second receiver pad configured to receive a second external voltage;
• a first multiplexer (MUX) connected to the first receiver pad and the second receiver pad;
• a second MUX connected to the first receiver pad and the second receiver pad;
• a receiver analog front end (RX AFE), the first MUX and the second MUX each being connected to an input terminal of the RX AFE;
• a clock data recovery (CDR) de-serializer connected to the RX AFE;
• a digital logic connected to the CDR de-serializer, the digital logic being configured to perform a loopback test on a reception path of a data signal by generating the data signal;
• and
• a serializer connected to the first MUX, the second MUX, and the digital logic.

A loopback test method for a transceiver, the method comprising:

• transmitting a data signal to a serializer;
• transmitting a serializer output signal from the serializer to a first multiplexer (MUX) and a second MUX;
• transmitting a first MUX output signal and a second MUX output signal to a receiver analog front end (RX AFE) based on a first external voltage input to a first receiver pad, a second external voltage input to a second receiver pad, and the serializer output signal, the transmitting including transmitting the first MUX output signal from the first MUX and transmitting the second MUX output signal from the second MUX;
• transmitting an RX AFE output signal from the RX AFE to a clock data recovery (CDR) de-serializer;
• transmitting a test target signal from the CDR de-serializer to a digital logic;
• and
• determining that a loopback test is passed when the data signal and the test target signal are the same.