Software modem with privileged mode decryption of control codes

摘要

A communications system includes a physical layer hardware unit and a processing unit. The physical layer hardware unit is adapted to communicate data over a communications channel in accordance with assigned transmission parameters and receive an incoming signal over the communications channel and sample the incoming signal to generate a digital received signal. The processing unit is adapted to execute a standard mode driver in a standard mode of operation and a privileged mode driver in a privileged mode of operation. The standard mode driver includes program instructions adapted to extract encrypted data from the digital received signal and pass the encrypted data to the privileged mode driver. The privileged mode driver includes program instructions adapted to decrypt the encrypted data to generate decrypted data including control codes and transfer the control codes to the physical layer hardware unit.