| 摘要 |
<p>PROBLEM TO BE SOLVED: To accelerate the pull-in-resetting of PN code signal to be tested into a PN code generating circuit after the occurrence of overflow and to improve accuracy in the supervisory of temporary error such as bit deviation. SOLUTION: Relating to a PN code reception circuit 100 for testing a transmission line, a pull-in-resetting control circuit 5 is provided for outputting a pull-in-resetting control signal for controlling the pull-in-resetting of PN code signal 101 to be tested and a pull-in-resetting instruction signal for instructing a selective PN code signal to a selector circuit 1 based on an overflow signal 201. Besides, an overflow detection circuit 4 outputs an overflow count signal showing the number of non-coincident bits with which the PN code signal to be tested and a reference PN code signal are not coincident and when the number of non-coincident bits exceeds a predetermined threshold value, the pull-in-resetting control circuit 5 outputs the pull-in-resetting instruction signal.</p> |
