| 摘要 |
<p>PURPOSE:To supervise mutually the operating state of opposite circuits by utilizing a function provided substantially with plural circuits operated independently in a reception frame synchronizing circuit being a circuit to be supervised. CONSTITUTION:A content 9 outputted from a counter circuit 9 is written in a buffer circuit 10 in a timing 4' delaying to some degree a pulse signal 4 outputted from a counter circuit 2. Further, a content 11 outputted from a buffer circuit 10 is written in a buffer circuit 12 in the same timing. Then the operating state of the reception frame synchronizing circuit, that is, the operating state of the counter circuit 1 is spervised by comparing the output content 11 and the output content 13 at a comparator circuit 14 in a timing retarding to some degree the timing 4'. That is, if the operation of the counter circuit 1 being the circuit to be supervised is stopped due to any fault, the operation of a counter circuit 6 counting the output number of times of an output pulse signal 3 is stopped also, a 2-input coincidence signal 15 is outputted from the comparator circuit 14 to detect generation of a fault of the reception frame synchronizing circuit.</p> |
