| 摘要 |
<p>PURPOSE:To make it possible to switch clocks under the running state of a system by forming a means for counting up the specific number of clocks. CONSTITUTION:When a flag 23 is turned on, a clock counting circuit CCC 24 starts to count up the number of system clocks supplied to a processor. At the time when a processor A 11 recognizes a time required for branch from a common firmware 22 in a peripheral device 2 to its firmwave A 110 by executing the succeeding branch instruction, the processor A 11 outputs a signal to switch the phase of an inner clock of the peripheral device 2 side to a clock switching circuit 21 at the timing of system clock decay, for instance, and functioned so as to invert the phase of the inner clock.</p> |
