tda9981bhl NXP Semiconductors, tda9981bhl Datasheet - Page 21

• Manufacturer Part Number: tda9981bhl
• Description: Hdmi Transmitter Up To 150 Mhz Pixel Rate With 3 ? 8-bit Video Inputs And 4 ? I 2s-bus With S/pdif
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TDA9981B_1
Product data sheet
8.14.4.1 E-EDID reading
8.14.1 Output HDMI buffers
8.14.2 Pixel repetition
8.14.3 HDMI and DVI receiver discrimination
8.14.4 DDC channel
8.14.5 RxSense detection
8.14 HDMI
An external resistor must be used to set the HDMI output amplitude. It has to be
connected between pin EXT_SWING and V
To transmit video formats with pixel rates below 25 MHz or to increase the number of
audio sample packets in each frame, the TDA9981B uses pixel repetition to increase the
transmitted pixel clock.
Table 16.
This information is located in the E-EDID receiver part, in the ’Vendor-Specific Datablock’
within the first CEA EDID timing extension. If the 24-bit IEEE registration identifier
contains the value 00 0C03h, then the receiver will support HDMI, otherwise the device
will be treated as a DVI device. However, the TDA9981B does not have direct access to
that information since E-EDID is read by an external microprocessor through the
TDA9981B I
The DDC-bus pins DDC_SDA and DDC_SCL are 5 V tolerant and can work at standard
mode (100 kHz).
In order to get receiver capabilities, the TDA9981B must read the E-EDID of the receiver.
This is made possible by temporarily connecting the I
microprocessor is able to read full EDID.
The TDA9981B is able to sense the connectivity and working behavior of the receiver. The
RxSense detection feature detects the presence of the 50
TMDS clock channel of the downstream site.
PIX_REP[3]
0
0
0
0
0
0
0
0
1
1
1
1
Pixel repetition
2
C-bus gate.
PIX_REP[2]
0
0
0
0
1
1
1
1
0
0
0
1
Rev. 01 — 4 July 2008
PIX_REP[1]
0
0
1
1
0
0
1
1
0
0
1
x
DDH(3V3)
150 MHz pixel rate HDMI transmitter
.
2
C-bus to the DDC lines, so that the
PIX_REP[0]
0
1
0
1
0
1
0
1
0
1
x
x
pull-up resistor R
TDA9981B
© NXP B.V. 2008. All rights reserved.
Pixel repeated
no repetition
once
twice
3 times
4 times
5 times
6 times
7 times
8 times
9 times
undefined
undefined
T
on the
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