Analog Devices Advantiv ADV7611 Hardware User's Manual page 33

Hardware User Guide
Notes
•
After EDID_A_ENABLE
address locations 0x7F, 0xFF, 0X17F, and 0x1FF in the internal EDID RAM with the computed checksums.
•
After power up, the ADV7611 E-EDID controller sets all bytes in the internal EDID RAM to 0, this operation takes less than 1 ms. It
is recommended to wait for at least 1 ms before initializing the EDID map with E-EDID.
•
When internal E-EDID is enabled on Port A, the hot plug should not be asserted until the EDID map has been completely initialized
with E-EDID.
•
The internal E-EDID can be accessed in read-only mode through the DDC interface at the I
•
The internal E-EDID can be accessed in read/write mode through the general I
TMDS EQUALIZATION
The ADV7611 incorporates active equalization of the HDMI data signals. This equalization compensates for the high frequency losses
inherent in HDMI and DVI cabling, especially at long lengths and higher frequencies. The ADV7611 is capable of equalizing for cable
lengths up to 30 meters and for pixel clock frequencies up to 225 MHz.
PORT SELECTION
HDMI_PORT_SELECT allows the selection of the active HDMI port. The only port on ADV7611 is Port A.
HDMI_PORT_SELECT[2:0], Addr 68 (HDMI), Address 0x00[2:0]
This two bit control is used for HDMI primary port selection.
Function
HDMI_PORT_SELECT[2:0]
000 (default)
TMDS CLOCK ACTIVITY DETECTION
The ADV7611 provides circuitry to monitor TMDS clock activity on HDMI port. The firmware can poll the appropriate registers for
TMDS clock activity detection and configure the ADV7611 as desired. TMDS clock detection control is active as soon as the ADV7611
detects activity above 25 MHz on the TMDS clock input.
PORT A E-EDID STRUCTURE
0x1FF
0x180
0x17F
0x100
0xFF
0x80
0x7F
0x00
Figure 4. Port A E-EDID Structure and Mapping for SPA Located in EDID Block 1
is set to 1, the ADV7611 EDID/repeater controller computes the checksums and updates the internal RAM
Description
Port A
BLOCK 2 CHECKSUM
0x1FE
BLOCK 3
BLOCK 2 CHECKSUM
0x17E
BLOCK 2
BLOCK 1 CHECKSUM
0xFE
BLOCK 1
BLOCK 0 CHECKSUM
0x7E
BLOCK 0
2
C interface at the EDID map I
Rev. A | Page 33 of 184
2
C address 0xA0.
2
C address.
UG-180