| 摘要 |
A mobile radio is disclosed which includes an integrated circuit audio processor which operates under the control of at least one microprocessor. The audio processor provides basic transmit/receive audio filters, tone signaling filters, squelch filters, an RF power level control circuit, a DC voltage measuring circuit, a volume level adjusting circuit, and a transmit level adjusting circuit. In the audio processor, audio bandwidth, tone filter response, squelch filter response and other operating characteristics are adjusted by an incoming data bit stream from the controlling microprocessor. In addition, in response to data received from a microprocessor, the audio processor is controlled, for example, to have its receive audio path closed and its transmit audio path opened to switch from the receive to transmit mode. Based on digital control data received at predetermined input pins, the audio processor of the present invention has its filter responses, signal paths, and other characteristics altered in a predetermined manner to configure the audio processor to appropriately operate in the transmit and receive modes.
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