Maxim Integrated MAX9277, Manual

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HDCP Authentication Procedures
The GMSL serializer generates a 64-bit random number
exceeding the HDCP requirement. The GMSL serial -
izer/deserializer internal one-time programmable (OTP)
memories contain a unique HDCP keyset programmed at
the factory. The host µC initiates and controls the HDCP
authentication procedure. The GMSL serializer and dese -
rializer generate HDCP authentication response values
for the verification of authentication. Use the following
procedures to authenticate the HDCP GMSL encryption
(refer to the HDCP 1.3 Amendment for GMSL for details).
The µC must perform link integrity checks while encryp -
tion is enabled (see Table 16 ). Any event that indicates
that the deserializer has lost link synchronization should
retrigger authentication. The µC must first write 1 to the
RESET_HDCP bit in the GMSL serializer before starting
a new authentication attempt.
HDCP Protocol Summary
Table 15 , Table 16 , and Table 17 list the summaries of the
HDCP protocol. These tables serve as an implementation
guide only. Meet the requirements in the GMSL amend -
ment for HDCP to be in full compliance.
Table 15. Startup, HDCP Authentication, and Normal Operation (Deserializer is not a
Repeater)—First Part of the HDCP Authentication Protocol
NO. µC HDCP GMSL SERIALIZER HDCP GMSL DESERIALIZER
1 Initial state after power-up.
Powers up waiting for HDCP
authentication.
Powers up waiting for HDCP
authentication.
2
Makes sure that A/V data not requiring
protection (low-value content) is available at
the GMSL serializer inputs (such as blue or
informative screen). Alternatively, uses the
FORCE_VIDEO and FORCE_AUDIO bits of
the GMSL serializer to mask A/V data at the
input of the GMSL serializer. Starts the link by
writing SEREN = H or link starts automatically
if
AUTOS
is low.
— —
3 —
Starts serialization and transmits
low-value content A/V data.
Locks to incoming data stream and
outputs low-value content A/V data.
4
Reads the locked bit of the deserializer and
makes sure the link is established.
— —
5
Optionally writes a random-number seed to
the GMSL serializer.
Combines seed with internally
generated random number. If
no seed provided, only internal
random number is used.
—
6
If HDCP encryption is required, starts
authentication by writing 1 to the
START_AUTHENTICATION bit of the GMSL
serializer.
Generates (stores) AN, and
resets the
START_AUTHENTICATION bit
to 0.
—
7
Reads AN and AKSV from the GMSL
serializer and writes to the deserializer.
—
Generates R0’ triggered by the μC’s
write of AKSV.
8
Reads the BKSV and REPEATER bit from the
deserializer and writes to the GMSL serializer.
Generates R0, triggered by the
µC’s write of BKSV.
—
MAX9277/MAX9281 3.12Gbps GMSL Serializers for Coax or
STP Output Drive and LVDS Input
www.maximintegrated.com
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