Enabling Luts; Video Configuration And Routing; Video Pipe Selection; Video Pipe Routing Registers - Analog Devices MAX96752 User Manual

LUT translation values will not readback correctly (e.g., 0xFF) in GMSL2 devices unless valid video data is received
by the deserializer. The internal block is powered down until valid video data is received.
However, writes to the LUT are always valid (even when valid video data does not exist) if the I2C/UART ACK is
received to confirm the register write. To confirm the LUT values by reading back via I2C/UART, valid video data is
required.

Enabling LUTs

Although LUT_A, LUT_B, and LUT_C have separate enable registers in GMSL2 devices, the LUTs cannot be enabled
partially. All LUTs (i.e., LUT_A, LUT_B, and LUT_C) in a single video pipe must be enabled/disabled together for
proper operation.
If configuration of a single color LUT is required, but the others are not, configure the single LUT with the desired
translation values and the remaining LUTs with 1:1 mapping values. For example, if only red color translation is
needed, populate LUT_A with the desired translation values and fill green (LUT_B) and blue (LUT_C) with the linear
1:1 translation values.

Video Configuration and Routing

Video Pipe Selection

Video pipes must be configured to match video streams between the deserializer and serializer. This programming
step is typically done following link initialization and ensures that the deserializer properly receives video data
from the serializer. By default, the deserializer is programmed to accept the most common stream from the
serializers, and configuration is not usually needed.

Video Pipe Routing Registers

Select the serializer stream ID to match the video streams (STR_ID) from the serializers for each deserializer video
pipe. GMSL serializers can have up to four video pipes (X, Y, Z, and U). These are annotated as 2 bits representing
the stream ID (Ex. Pipe X = 0b00, Pipe Y = 0b01, Pipe Z = 0b10, and Pipe U = 0b11). GMSL display deserializers have
usually one video pipe which is also annotated as 2 bits representing the stream ID.
By default, the MAX96752 serializer video pipes are turned on and stream ID 0b00 is selected.
Table 4. MAX96752 Video Pipe Routing Registers
Register Bitfield Name
Address
0x50 STR_SEL[1:0]

Dual oLDI Deserializer Video Configuration and Routing

Overview

OpenLDI (oLDI) is a high-bandwidth digital-video interface that uses low-voltage differential signaling (LVDS) to
transmit digital video without digital-to-analog conversion or complex decoding protocols. GMSL2 oLDI
deserializers convert single- or dual-link GMSL2 input to single or dual oLDI video output with flexible output
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Bits POR
1:0 0b00 0b00: Receive str_id=00
0b01: Receive str_id=01
0b10: Receive str_id=10
0b11: Receive str_id=11
Decode
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