Analog Devices Advantiv ADV7611 Hardware User's Manual page 177

Hardware User Guide
DDC PORTS
2
An I C port, DDC Port A, allows HDMI hosts to access the internal E-EDID and the HDCP registers. Note that the DDC ports are 5 V
tolerant, which simplifies the hardware between the HDMI connector and the ADV7611.
2
I C Protocols for Access to the Internal EDID
2
An I C master connected on a DDC port can access the internal EDID using the following protocol:

Write sequence, as defined in the Protocol for Main I2C Port section

Read sequence, as defined in the Protocol for Main I2C Port section

Current address read sequence:
Allows the master on the DDC port to read access internal E-EDID without specifying the subaddress that must be read. The
ADV7611 stores an address counter for DDC port that maintains the value of the subaddress that was last accessed. The address
counter is incremented by one every time a read or a write access is requested on the DDC port.
CURRENT ADDRESS
READ SEQUENCE
S = START BIT
P = STOP BIT
A(S) = ACKNOWLEDGE BY SLAVE
A(M) = NO ACKNOWLEDGE BY MASTER
2
I C Protocols for Access to HDCP Registers
2
An I C master connected on a DDC port can access the internal EDID using the following protocol:

Write sequence, as defined in the Protocol for Main I2C Port section

Read sequence, as defined in the Protocol for Main I2C Port section

Short read format, as defined in the High-bandwidth Digital Content Protection (HDCP) System Specifications
DDC Port A
The DDC lines of the HDMI Port A comprise the DDCA_SCL and DDCA_SDA pins. An HDMI host connected to the DDC Port A
accesses the internal E-EDID at address 0xA0 in read only mode, and the HDCP registers at address 0x74 in read/write mode (refer to
Figure 69). The internal E-EDID for Port A is described in the Structure of Internal E-EDID section.
Refer to the High-bandwidth Digital Content Protection (HDCP) System Specifications for detailed information on the HDCP registers.
LSB = 1
S SLAVE ADDRESS A(S)
Figure 68. Current Address Read Sequence
INTERNAL E-EDID
SA: 0xA0
DDCA_SCL
DDCA_SDA
Figure 69. Internal E-EDID and HDCP Registers Access from Port A
(SA = Slave Address)
Rev. A | Page 177 of 184
DATA(1) A(S)
HDCP REGISTERS
SA: 0x74
UG-180
DATA(N) A(M) P