Circuit Descriptions
7.
7.4
HDMI
Refer to
for the HDMI architecture.
Figure 7-6 HDMI architecture
Below find an explanation of the signals that are used:
•
DDC: EDID information is read through the I
2
C lines and is
used for the HDCP authentication process as well
•
CEC: connected to MT5392 and all HDMI input ports
directly
•
EDID_WC: used to disable the write protection pin of the
EEPROM; when updating the EEPROM, pull this pin LOW
•
TMDS: signal that contains video and audio
•
HOTPLG: to initiate the source device for EDID reading
and HDCP authentication
•
5V: to indicate the presence of the source device for the
acknowledgement of the MT5392.
7.5
USB
Refer to
for the USB architecture.
Figure 7-7 USB architecture
Below find an explanation of the signals that are used:
•
USB_OC:
–
normal operation signal level is “HIGH” (logic “1”)
–
when the 5V supply to the USB device exceeds a
current limit of 700 mA, the RT9715HGS will pull the
signal level to “LOW” state (logic “0”), which will restart
the set
–
if the die temperature exceeds 120 degrees C, the
signal will be “LOW” (logic “0”), which will restart the set
•
USB_PWR_EN: to enable or disable the USB power switch
RT9715HGS; to enable, this signal must be set to logic “0”
•
USB_DM, USB_DP: USB differential signal.
1
8
970_205_100
3
25.ep
s
100
3
25
MT5
3
92
HDMI
Connector 1
HDMI
Connector 2
HDMI
Connector
s
ide
ADV
3
002
TMD
S
DDC
TMD
S
DDC
TMD
S
DDC
5 V
HOTPLUG
HOTPLUG
5 V
5 V
HOTPLUG
TMD
S
DDC
Loc
a
l I2C
CEC
Re
s
et
EDID E2PROM
EDID I
2
C
EDID_WC
1
8
970_206_100
3
25.ep
s
100
3
25
MT5
3
92
GPIO 1
GPIO 2
U
S
B_PWE
U
S
B_OC
RT9715HG
S
U
S
B DM
U
S
B DP
VIN
VOUT
U
S
B
connector
5V
EN_
FLG_
+5V_
S
W
U
S
B _DM
U
S
B _DP
1D0
3
7D00
7400