The 38B7 group has six 8-bit timers, one 16-bit timer, a fluorescent display automatic display circuit, 16-channel 10-bit A-D converter, a serial I/O with automatic transfer function, which are available for controlling musical instruments and household appliances. The 38B7 group has variations of internal memory type. For details, refer to the section on part numbering. For details on availability of microcomputers in the 38B7 group, refer to the section on group expansion. Built-in pull-down resistors connected to high-breakdown voltage ports are available by specifying with the mask option in the mask ROM version. For the details, refer to the section on the mask option of pull-down resistor.