| 摘要 |
<p>PURPOSE:To control a reading to a PROM by permitting and prohibiting the reading of data written in the PROM by operating a signal outputted from an information storing part according to specific data written on the information storing part. CONSTITUTION:When a reading permitting signal 111 is the active-high of an initial state, and a reading control signal 110 and the specific data on a data bus are given to a reading control part 105-1, the reading control part 105-1 fixes the reading permitting signal 111 to an inactive-low. When the reading permitting signal 111 becomes the inactive-low, after that, since the signal outputted from an AND gate 104 becomes always the inactive-low even when a reading signal 100-1 for the PROM is transmitted as the active-high with a PROM writer 100, the data cannot be read from an OTP 101.</p> |
