| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a portable communication terminal capable of correcting a low speed clock in a simple circuit arrangement, using a high speed clock operative at a high accuracy only in a specified time zone. <P>SOLUTION: A high speed clock circuit 203 outputs a high speed clock signal 204 which is generated, though at a high accuracy, only when a transceiver 202 is acting. A low speed clock circuit 211 outputs a low speed clock signal 212 having a low accuracy, compared with it. A clock deviation detector 214 starts counting both clock signals 204, 212 at their output timings, obtain the deviation of a specified count value of the lower speed clock signal 212 from that of the high speed clock signal 204 just when this specified count value is reached, and stores the deviation in a clock deviation data memory 207, thereby using it for correcting the clock of the low speed clock signal 212. <P>COPYRIGHT: (C)2003,JPO |
