
4-54
Register Descriptions
AV_Desc (audio/video descramble)
0b010
This mode must be selected when the host or the Front
End Drive is ready to start A/V contents descrambling.
When the system incorporates a stand-alone DVD player,
the CSS unit extracts the title key from the sector header
area and recovers the active title key necessary for
descrambling the audio/video contents. In the audio/video
sector area (2048 bytes), the CSS unit descrambles the
audio/video contents based on the status of the scramble
control ag in the sector header. When a PC DVD drive
is used, the CSS unit only descrambles the audio/video
contents. The CSS unit extracts the Title Key while in the
Auth_TK mode (0b100).
Auth_DK (disc key authentication/extraction)
0b011
The L64021 uses this mode for disc key authentication
when a DVD disc is inserted on the PC DVD drive tray.
When the host sets this mode, the CSS unit generates
the challenge data and an interrupt, which informs the
host that the data is ready for authentication (see
Register 176, bit 0). Once the challenge data is ready, the
host can begin authentication according to the host
Auth_TK (title key authentication/decryption)
0b100
When a PC DVD drive is incorporated in the system, the
host must select this mode to play the DVD title. When
the host selects this mode, the CSS Unit generates the
challenge data and an interrupt, which informs the host
that the code is ready for authentication (see Register
176, bit 0). Once the challenge data is ready, the host
can begin authentication according to the host control
CSS Software Reset
W 3
When the host sets this bit, it initializes the CSS unit. This
software reset functions in the same manner as a hard
reset (power-on reset), with the exception that the host
register settings for the decrypted disc and title keys are
maintained.
Reserved
7:4
Register 179 (0x0B3)
Reserved
[7:0]