TDA19977A_TDA19977B_1
NXP B.V. 2008. All rights reserved.
Product data sheet
Rev. 01 — 7 August 2008
11 of 40
NXP Semiconductors
TDA19977A; TDA19977B
Triple input HDMI receiver interface with digital processing
8.4 Equalizer
The auto-adaptive equalizer automatically measures and selects the settings which
provide the best signal quality for each cable. This improves signal quality and enables the
use of cable lengths up to 25 m (laboratory tested, contact NXP for detailed information).
The equalizer is fully automatic and consequently does not need any external control.
8.5 Activity detection
The TDA19977A; TDA19977B uses activity detection to automatically select the active
HDMI input. An internal, fully programmable, frequency lter controls activity detection. It
sees only the activity on the HDMI inputs with a frequency range between fmin (22.5 MHz)
and fmax (235 MHz).
This activity detection can generate an interrupt enabling users to manage each HDMI
input.
8.6 High-bandwidth digital content protection (TDA19977A only)
The HDMI receiver also contains the HDCP decryption function. The keys provided by the
OTP non-volatile memory in encrypted format are decrypted and then stored in the HDCP
module. This is particularly suitable for repeater applications. The TDA19977A manages
all HDCP repeater functions based on the HDCP 1.2 specication.
Three DDC-buses HSCLA/HSDAA; HSCLB/HSDAB and HSCLC/HSDAC are integrated
into the HDCP function, one bus for each HDMI input. The DDC-bus connected to the
HDCP block is automatically selected based on the active HDMI input. The unused inputs
are disconnected from the DDC-bus (no acknowledge). No additional CPU processing is
required because the authentication phase and the re-key calculation are fully managed
by the TDA19977A.
8.7 Color depth unpacking
In Deep Color mode, the TDA19977A; TDA19977B receives several fragments of a pixel
group at the HDMI link frequency. This block translates the received pixel group into pixels
at the pixel frequency. This operation is fully automatic and does not need any external
control.
8.8 Derepeater
The HDMI source uses pixel repetition to increase the transmitted pixel clock for
transmitting video formats at native pixel rates below 25 Mpixel/s or to increase the
number of audio sample packets in each line. The derepeater function discards repeated
pixels and divides the clock to reproduce the native video format.
8.9 Upsample
The HDMI source can use YCbCr 4:2:2 pixel encoding which enables the number of bits
allocated per component to be increased up to 12. The upsample function transforms this
12-bit YCbCr 4:2:2 data stream into a 12-bit YCbCr 4:4:4 data stream by repeating or
linearly interpolating the chrominance pixels Cb and Cr.
Upsampling mode is selected using the I2C-bus.