Introduction of short circuit cap: short circuit cap is also called jumper cap, which is usually used on single chip microcomputer. For example, a single row of pins are used for short circuit. Two adjacent pins can be short circuited with a short circuit block, that is, the connection on the circuit can be realized. For example, there is a three wire pin, and a short circuit block can realize the function of dial switch. It is used to connect the pins of peripheral module and MCU. After the short-circuit cap is removed, the single-chip pin is not connected with any module.