Quantum Data 881 - Manual (Page 616)

598 Chapter 18 Testing HDCP
3. Check Bcaps over the Aux Channel DPCD address 0x68028 to determine if the sink is
a receiver or a repeater and generate a new An value (8 byte random session number)
in the transmitter.
4. Transmitter writes An to the receiver over the Aux Channel to DPCD address 0x6800C.
5. Transmitter writes Aksv to the receiver over the Aux Channel to DPCD address
0x68007.
6. Read Bksv from the receiver over the Aux Channel bus from DPCD address 0x68000
and validate that it has exactly 20 zeroes and 20 ones in it. You can query this value
with the following command:
dptx:dpcd? 680000 5
The display may return a value such as the following which is:
07BE05CEA9
The value in binary is 0000011110111110000001011100111010101001 which contains 20
zeros and 20 ones.
7. Write the Bksv value to the transmitter to trigger calculation of R0.
8. Wait for the R0 calculation in the transmitter to complete.
9. Wait for at least 100 milliseconds and then read the R0' value out of the receiver over
the Aux Channel from DPCD address 0x68005 and compare the value with the R0
calculation in the transmitter. If this step fails, then go to step 1.
10. Enable encryption and read Bstatus over the Aux Channel at DPCD address 0x68029
to determine if a Link Verification Failure has occurred.