| 摘要 |
<p>PURPOSE:To easily set a threshold level and to improve the general usefulness by inputting a received signal to plural reception circuits different in threshold and selecting the reception circuit having an optimum threshold level to connect it to a CPU. CONSTITUTION:The signal received by an antenna 11 is inputted to reception circuits 101 to 104 different in threshold level, and data is detected. A selector circuit 9 selects the reception circuit having an optimum threshold level to connect it to a CPU 1. Data detected by the selected circuit 10 passes a demodulating circuit 7, an UART 4, and a bus 5 is inputted to the CPU 1 and is subjected to data processing. This data is stored in a RAM 3 and is transmit ted by a transmission circuit 8 on demand. The threshold level is easily set in accordance with circumstances and conditions of the use to obtain a card of high general usefulness.</p> |
