DS90UB901Q_15 Datasheet, PDF (35/50 Pages) Texas Instruments – 10 - 43MHz 14 Bit Color FPD-Link III Serializer and Deserializer with Bidirectional Control Channel

DS90UB901Q, DS90UB902Q
www.ti.com
SNLS322E – JUNE 2010 – REVISED APRIL 2013
Once Step 3 is complete, AT SPEED BIST is over and the Deserializer is out of BIST mode. To fully return to
Normal mode, apply Normal input data into the Serializer.
Any PASS result will remain unless it is changed by a new BIST session or cleared by asserting and releasing
PDB. The default state of PASS after a PDB toggle is HIGH.
It is important to note that AT SPEED BIST will only determine if there is an issue on the link that is not related to
the clock and data recovery of the link (whose status is flagged with LOCK pin).
LVCMOS VDDIO OPTION
1.8V or 3.3V SER Inputs and DES Outputs are user seletable to provide compatibility with 1.8V and 3.3V system
interfaces.
REMOTE WAKE UP (Camera Mode)
After initial power up, the Serializer is in a low-power Standby mode. The Deserializer (controlled by ECU/MCU)
'Remote Wake-up' register allows the Deserializer side to generate a signal across the link to remotely wake-up
the Serializer. Once the Serializer detects the wake-up signal Serializer switches from Standby mode to active
mode. In active mode, the Serializer locks onto PCLK input (if present), otherwise the on-chip oscillator is used
as the input clock source. Note the MCU controller should monitor the Deserializer LOCK pin and confirm LOCK
= H before performing any I²C communication across the link.
For Remote Wake-up to function properly:
• The chipset needs to be configured in Camera mode: Serializer MODE = 0 and Deserializer MODE = 1
• Serializer expects remote wake-up by default at power on.
• Configure the control channel driver of the Deserializer to be in remote wake-up mode by setting Deserializer
Register 0x26h = 0xC0h.
• Perform remote wake-up on Serializer by setting Deserializer Register 0x01 b[2] = 1
• Return the control channel driver of the Deserializer to the normal operation mode by setting Deserializer
Register 0x26h = 0x00h
• Configure the control channel driver of the Deserializer to be in normal operation mode by setting Deserializer
Register 0x27h = 0xC0h.
Serializer can also be put into standby mode by programming the Deserializer remote wake-up control register
0x01 b[2] REM_WAKEUP to 0.
POWERDOWN
The SER has a PDB input pin to ENABLE or Powerdown the device. The modes can be controlled by the host
and is used to disable the Link to save power when the remote device is not operational. An auto mode is also
available. In this mode, the PDB pin is tied High and the SER switches over to an internal oscillator when the
PCLK stops or not present. When a PCLK starts again, the SER will then lock to the valid input PCLK and
transmits the data to the DES. In powerdown mode, the high-speed driver outputs are static (High).
The DES has a PDB input pin to ENABLE or Powerdown the device. This pin can be controlled by the system
and is used to disable the DES to save power. An auto mode is also available. In this mode, the PDB pin is tied
High and the DES will enter powerdown when the serial stream stops. When the serial stream starts up again,
the DES will lock to the input stream and assert the LOCK pin and output valid data. In powerdown mode, the
Data and PCLK outputs are set by the OSS_SEL control register.
POWER UP REQUIREMENTS AND PDB PIN
It is required to delay and release the PDB input signal after VDD (VDDn and VDDIO) power supplies have
settled to the recommended operating voltages. A external RC network can be connected to the PDB pin to
ensure PDB arrives after all the VDD have stabilized.
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