DS90UB924-Q1 Datasheet, PDF (21/62 Pages) Texas Instruments – 5-MHz to 96-MHz 24-bit Color FPD-Link III to OpenLDI Deserializer With Bidirectional Control Channel

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DS90UB924-Q1
SNLS512 – APRIL 2016
Feature Description (continued)
7.3.10.2 Color Modes
By default, the Pattern Generator operates in 24-bit color mode, where all bits of the red, green, and blue outputs
are enabled. 18-bit color mode can be activated from the configuration registers (Table 8). In 18-bit mode, the 6
most significant bits (bits 7-2) of the Red, Green, and Blue outputs are enabled; the 2 least significant bits are 0.
7.3.10.3 Video Timing Modes
The Pattern Generator has two video timing modes – external and internal. In external timing mode, the Pattern
Generator detects the video frame timing present on the DE and VS inputs. If Vertical Sync signaling is not
present on VS, the Pattern Generator determines Vertical Blank by detecting when the number of inactive pixel
clocks (DE = 0) exceeds twice the detected active line length. In internal timing mode, the Pattern Generator
uses custom video timing as configured in the control registers. The internal timing generation may also be
driven by an external clock. By default, external timing mode is enabled. Internal timing or Internal timing with
External Clock are enabled by the control registers (Table 8). If internal clock generation is used, register 0x39
bit 1 must be set.
7.3.10.4 External Timing
In external timing mode, the pattern generator passes the incoming DE, HS, and VS signals unmodified to the
video control outputs after a two-pixel clock delay. It extracts the active frame dimensions from the incoming
signals in order to properly scale the brightness patterns. If the incoming video stream does not use the VS
signal, the Pattern Generator determines the Vertical Blank time by detecting a long period of pixel clocks without
DE asserted.
7.3.10.5 Pattern Inversion
The Pattern Generator also incorporates a global inversion control, located in the PGCFG register, which causes
the output pattern to be bitwise-inverted. For example, the full-screen Red pattern becomes full-screen cyan, and
the Vertically Scaled Black to Green pattern becomes Vertically Scaled White to Magenta.
7.3.10.6 Auto Scrolling
The Pattern Generator supports an Auto-Scrolling mode, in which the output pattern cycles through a list of
enabled pattern types. A sequence of up to 16 patterns may be defined in the registers. The patterns may
appear in any order in the sequence and may also appear more than once.
7.3.10.7 Additional Features
Additional pattern generator features can be accessed through the Pattern Generator Indirect Register Map. It
consists of the Pattern Generator Indirect Address (PGIA — Table 8) and the Pattern Generator Indirect Data
(PGID — Table 8).
7.3.11 Serial Link Fault Detect
The DS90UB924-Q1 can detect fault conditions in the FPD-Link III interconnect. If a fault condition occurs, the
Link Detect Status is 0 (cable is not detected) on bit 0 of address 0x1C (Table 8). The device detects any of the
following conditions:
1. Cable open
2. RIN+ to - short
3. RIN+ to GND short
4. RIN- to GND short
5. RIN+ to battery short
6. RIN- to battery short
7. Cable is linked incorrectly (RIN+/RIN- connections reversed)
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