| 摘要 |
PURPOSE:To effectively utilize a display by so constructing a digital clock for car that the transfer data of a microcomputer mounted on a vehicle are displayed. CONSTITUTION:A time measuring counter 2 receives the original oscillation signals from an oscillator 1 to form time measuring data and, after corrected by a measured time correcting circuit 7, outputs the data to a display changeover circuit 3. On the other hand, a serial data register 9 holds the data serially transferred from a microcomputer 10 and outputs the data to the circuit 3 based on the state signals from a sensor 11. The circuit 3 selects either of the data of the counter 2 and the data of the register 9 by the output of a changeover signal generating circuit 8 and outputs the selected data to a decoder circuit 4. The circuit 4 converts the received data to those corresponding to display signals and transfers them to a display driver 5. The driver 5 drives the display elements of a display 6. When a changeover switch 8a is turned ON, a changeover signal is generated 8, the selection of the time measuring data is stopped in the circuit 3 and the data of the register 9 are selected to be displayed 6. |
