Abstract: A Scan test in a single-wire bus circuit is described in the present disclosure. The single-wire bus circuit has one or more external pins for connecting to a single-wire bus. Given that multiple physical pins are required to carry out the Scan test, the single-wire bus circuit must provide additional pins required by the Scan test. In embodiments disclosed herein, the single-wire bus circuit includes a communication circuit under test and a driver circuit coupled to the communication circuit via multiple internal pins. The driver circuit uses a subset of the internal pins as input pins and another subset of the internal pins as output pins in order to carry out the Scan test in the communication circuit. A mini-telegram is sent at the beginning of the Scan test along with common bus values. This reduces the time required to perform the scan test.