DS90UH927Q-Q1 Datasheet, PDF (20/68 Pages) Texas Instruments – 5-MHz to 85-MHz 24-Bit Color FPD-Link III Serializer with HDCP

DS90UH927Q-Q1
SNLS433C – NOVEMBER 2012 – REVISED JANUARY 2015
www.ti.com
Feature Description (continued)
7.3.8.4 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.
7.3.8.5 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.
7.3.8.6 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.
7.3.9 Remote Auto Power Down Mode
The DS90UH927Q-Q1 serializer features a Remote Auto Power Down mode. This feature is enabled and
disabled through the register bit 0x01[7] (Table 5). When the back channel is not detected, either due to an idle
or powered-down deserializer, the serializer enters remote auto power down mode. Power dissipation of the
serializer is significantly reduced in this mode. The serializer automatically attempts to resume normal operation
upon detection of an active back channel from the deserializer. To complete the wake-up process and reactivate
forward channel operation, the remote power-down feature must be disabled by either a local I²C host, or by an
auto-ACK I²C transaction from a remote I²C host located at the deserializer. The Remote Auto Power Down
Sleep/Wake cycle is shown below in Figure 16:
Enable
Set reg_0x01[7]=1
Back Channel IDLE
Normal Operation
Remote Auto Power
Down Enabled
Forward-channel
OFF
Sleep
Disable
Set reg_0x01[7]=0
Back Channel ACTIVE
Figure 16. Remote Auto Power Down Sleep/Wake Cycle
To resume normal operation, the Remote Auto Power Down feature must be disabled in the device control
register. This may be accomplished from a local I²C controller by writing reg_0x01[7]=0 (Table 5). To disable
from a remote I²C controller located at the deserializer, perform the following procedure to complete the wake-up
process:
1. Power up remote deserializer (back channel must be active)
2. Enable I²C PASS-THROUGH ALL by setting deserializer register reg_0x05[7]=1
3. Enable I²C AUTO ACK by setting deserializer register reg_0x03[2]=1
4. Disable Remote Auto Power Down by setting serializer register reg_0x01[7]=0
5. Disable I²C AUTO ACK by setting deserializer register reg_0x03[2]=0
20
Submit Documentation Feedback
Copyright © 2012–2015, Texas Instruments Incorporated
Product Folder Links: DS90UH927Q-Q1