| 摘要 |
<p>A microcontroller 100 for processing caller information received from a telephone line for display on a display panel of a telecommunication device has a display control unit 110, a ring detector 140, a carrier detector 150, and a caller ID unit 130 with a CPU 160 and a demodulator 132 which converts the received analog caller ID data into digital data. To save power, particularly in a battery powered portable device, a power management unit 134 enables the power supply 170 to the demodulator 132 in response to detection of a first ring by the ring detector 140. After the demodulator 132 has processed all the caller ID information, the demodulator power supply 170 is disabled in response to the carrier detector 150 no longer detecting a carrier with caller information. The demodulator 132 incorporates a sigma delta converter (202, Fig.2) which converts the caller information to a two-level quantized digital format, a digital filter (204) for noise filtering, and a demodulator (206) which demodulates the caller information to a digital baseband signal. The digital implementation of the demodulator 132 as part of the caller ID unit 130 integrated with the microcontroller 100 provides cost savings over the prior art use of an analog switched capacitor filter (302, Fig.3) in a demodulator which is coupled to a separate microcontroller.</p> |
