| 摘要 |
<p>PURPOSE:To inform the started frequency by displaying the system clock frequency which is used in accordance with the designating operation of a system clock carried out to a CPU. CONSTITUTION:When a system clock signal A to be supplied to a CPU is designated by a CPU clock designating device 1, a CPU clock selection signal 2 is transmitted to a CPU clock selecting device 3. The signal A is displayed by sending the system clock display data 4 and 5 consisting of 4 bits, for example, to the selectors 8 and 9 and then giving these data to the clock display devices 16a and 16b via the 7-segment decoders 12 and 13 respectively. Both decoders 12 and 13 transmit the high-order and low-order digit drive signals 14 and 15, respectively. In such a way, the system clock frequency is displayed and therefore the frequency can always be reported to an operator.</p> |
