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Table 18. HDCP Authentication and Normal Operation (One Repeater, Two µCs)—First
and Second Parts of the HDCP Authentication Protocol (continued)
NO.
µC_B
µC_R
HDCP GMSL
SERIALIZER
(TX_B1, TX_R1,
TX_R2)
HDCP GMSL
DESERIALIZER
(RX_R1, RX_D1,
RX_D2)
TX_B1 CDS = 0
TX_R1 CDS = 0
TX_R2 CDS = 0
RX_R1 CDS = 1
RX_D1 CDS = 0
RX_D2 CDS = 0
8
—
When GPIO_1 = 1 is detected,
starts and completes the first part
of the authentication protocol
between the (TX_R1, RX_D1)
and (TX_R2, RX_D2) links (see
).
TX_R1, TX_R2:
According to commands
from µC_R, generates
AN, computes R0.
RX_D1, RX_D2:
According to commands
from µC_R, computes
R0’.
9
Waits for the VSYNC falling
edge and then enables
encryption on the (TX_B1,
RX_R1) link. Full authentication
is not complete yet so it makes
sure A/V content that needs
protection is not transmitted.
Since REPEATER = 1 was read
from RX_R1, the second part of
authentication is required.
—
TX_B1: Encryption
enabled after next
VSYNC falling edge.
RX_R1: Decryption
enabled after next
VSYNC falling edge.
10
—
When GPIO_0 = 1 is detected,
enables encryption on the
(TX_R1, RX_D1) and (TX_R2,
RX_D2) links.
TX_R1, TX_R2:
Encryption enabled
after next VSYNC
falling edge.
RX_D1, RX_D2:
Decryption enabled
after next VSYNC
falling edge.
11
Waits for some time to allow
µC_R to make the KSV list
ready in RX_R1. Then polls
(reads) the KSV_LIST_READY
bit of RX_R1 regularly until
proper acknowledge frame is
received and bit is read as 1.
Blocks control channel
from μC_B side by setting
REVCCEN = FWDCCEN = 0
in RX_R1. Retries until proper
acknowledge frame received.
—
RX_R1: Control
channel from serializer
side (TX_B1) is blocked
after FWDCCEN =
REVCCEN = 0 is
written.
12
Writes BKSVs of RX_D1 and
RX_D2 to the KSV list in RX_
R1. Then, calculates and writes
the BINFO register of RX_R1.
—
RX_R1: Triggered by
µC_R’s write of BINFO,
calculates hash value
(V’) on the KSV list,
BINFO and the secret-
value M0’.
13
Writes 1 to the KSV_LIST_
READY bit of RX_R1 and then
unblocks the control channel
from the µC_B side by setting
REVCCEN = FWDCCEN = 1 in
RX_R1.
—
RX_R1: Control channel
from the serializer side
(TX_B1) is unblocked
after FWDCCEN =
REVCCEN = 1 is
written.
MAX9277/MAX9281
3.12Gbps GMSL Serializers for Coax or
STP Output Drive and LVDS Input
www.maximintegrated.com
Maxim Integrated │
55