| 摘要 |
A digital television (DTV) system comprises a front-end circuit comprises a demodulator circuit for producing a non-decrypted transport stream signal; a back-end circuit for decoding transport stream data; an external memory coupled to the back-end circuit; an address bus and a data bus to which the external memory is coupled through a plurality of address and data pins; a cryptocard module coupled to the front-end circuit and the back-end circuit for decrypting transport stream data to produce a decrypted transport stream signal and for performing conditional access and security functions, the cryptocard module having address and data pins coupled to address and data pins of the external memory; and a switching means for providing either the non-decrypted transport stream signal produced by the front-end circuit or the decrypted transport stream signal produced by the cryptocard module to the back-end circuit.
|
