Datasheet

HPD1
SDA1
SCL1
HPD2
SDA2
SCL2
HPD3
SDA3
SCL3
EQ
S1
S2
HPD_SINK
SDA_SINK
SCL_SINK
Y1/Z1
Y2/Z2
Y3/Z3
Y4/Z4
VSADJ
E-EDID
HDMIRX
DDC_SDA
DDC_SCL
5V
5V
5V
47kW
47kW
47kW
mController
3.3V
4.7kW 4.7kW
CEC
CEC
CEC
4.02 kW 10%
GND
1kW
HPD
5V
SDA
SCL
CEC
CLK
D 0
HPD
5V
SDA
SCL
CEC
CLK
D0
D1
D2
HPD
5V
SDA
SCL
CEC
CLK
D0
D1
D2
SINK
HPD
5V
SDA
SCL
CEC
CLK
D0
D1
D2
SOURCE1
HPD
5V
SDA
SCL
CEC
CLK
D0
1D
D2
D1
D2
SOURCE2
HPD
5V
SDA
SCL
CEC
CLK
D0
D1
D2
SOURCE3
A11/B11
A12/B12
A13/B13
A14/B14
VDD
(5V)
VCC
(3.3V)
A21/B21
A22/B22
A23/B23
A24/B24
A31/B31
A32/B32
A33/B33
A34/B34
Y1/Z1
Y2/Z2
Y3/Z3
Y4/Z4
TMDS361B
SLLS988A –SEPTEMBER 2009–REVISED JULY 2011 www.ti.com
A DTV Supporting a Passive CEC Link
In Figure 46, the DTV does not have the capability of handling CEC signals, but allows CEC signals to pass over
the CEC bus. The source selection is done by the control command of the DTV. The user cannot force the
command from any audio/video product on the CEC bus. The selected source reads the E-EDID data after
receiving an asserted HPD signal. The microcontroller loads different CEC physical addresses while changing
the source by means of the S1 and S2 pins.
E-EDID Reading Configurations in Standby Mode
When the DTV system is in standby mode, the sources do not read the E-EDID memory because the 1-kΩ
pulldown resistor keeping the HPD_SINK input at logic-low forces all HPD pins to output logic-low to all sources.
The source does not read the E-EDID data with a low on the HPD signal. However, if reading the E-EDID data in
the system standby mode is preferred, then the TMDS361B can still support this need.
The recommended configuration sequences are:
1. Apply the same 3.3-V power to the VCC of the TMDS361B and the TMDS line termination at the HDMI
receiver.
2. Because the TMDS361B has clock-detect circuitry and there is no valid input TMDS clock in the standby
mode, the TMDS361B draws significanty less current.
3. Set S1 and S2 to select the source port which is allowed to read the E-EDID memory.
Note that if the source has a time-out limitation between the 5-V and the HPD signals, the foregoing configuration
is not applicable. Uses individual EEPROMs assigned for each input port, see Figure 47. The solution uses
E-EDID data to be readable during system power-off or standby-mode operations.
Figure 46. Three-Port HDMI-Enabled DTV With TMDS361B – CEC Commands Passing Through
32 Copyright © 2009–2011, Texas Instruments Incorporated