| 摘要 |
A system and method for providing soft modem and soft audio copy protection for hardware interfaces and software code utilized in an AC '97 architecture to prevent against unauthorized copying. The system confirms that a codec connected to the AC '97 architecture is provided by a desired supplier. The system performs a sample rate negotiation to determine an operating sample rate for data transfer. When the system provides a desired sample rate which does not correspond to a sample rate appearing in a predefined set of sample rates supported by an AC '97 architecture, the system expects the codec to echo back a predesignated sample rate during the sample rate negotiation indicating that a desired sample rate has been received which does not correspond to one of the supported sample rates. When the system determines that the predesignated sample rate has been echoed back, the copy protection system recognizes the codec as being provided by an authorized supplier and authorizes the codec for operation. However, the system disables the attached codec when it determines that the predesignated sample rate has not been echoed back from the codec in response to reading an unsupported sample rate from the control register. This provides the security feature of ensuring that the attached codec is provided by an authorized supplier.
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