PURPOSE: To utilize an I/O controlling terminal effectively by connecting a shift register to an I/O port provided with a serial buffer for a microcomputer and connecting display lamps in accordance with respective bit positions.
CONSTITUTION: When a serial buffer SB is used as an internal register of a microcomputer CPU in the display lamp controlling method, one I/O port is used to output data DA and a clock CL to a shift register SF. The display lamps 1∼8 are connected in accordance with respective bit positions of respective shift registers and the respective lamps 1∼8 are cotrolled on/off by the data set up in the shift registers. In the controlling method, the limited I/O terminal is used to control on/off of the plural lamps, so that the I/O port can be effectively used.
MORI HIROYUKI
INOUE SHINICHI
MURAI ATSUYA
| JPS569064A | 1981-01-29 |