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Sleep Mode
The serializers have sleep mode to reduce power con
-
sumption when powered up. The devices enter or exit
sleep mode by a command from a local µC or a remote
µC using the control channel. Set the SLEEP bit to 1 to
initiate sleep mode. Entering sleep mode resets the HDCP
registers, but not the configuration registers. The serializ
-
er sleeps immediately after setting its SLEEP = 1. The
serial outputs has a wake-up receiver to accept wake-up
commands from the attached deserializer. Wake-up from
the remote side is not supported in coax splitter mode.
Disable the wake-up receiver (through DISRWAKE), if
wake-up from remote side is not used in order to reduce
sleep mode current. If the wake-up receiver is disabled,
the device can only be woken up from the local control
channel. See the
Link Startup Procedure
section for
details on waking up the device for different µC and start
-
ing conditions.
To wake up from the local or remote side, send an arbi
-
trary control channel command to serializer, wait for 5ms
for the chip to power up and then write 0 to SLEEP regis
-
ter bit to make the wake-up permanent.
The serializer cannot power up into sleep mode when
CDS = 0 (for LCD applications), however after power-up,
the device can be put to sleep.
Power-Down Mode
The serializers have a power-down mode which fur
-
ther reduces power consumption compared to Sleep
Mode. Set
PWDN
low to enter power-down mode. In
power-down, the serial outputs remain high impedance.
Entering power-down resets the device’s registers. Upon
exiting power-down, the state of external pins CONF[1:0],
ADD[2:0], CX/TP, GPO/HIM and BWS are latched.
Configuration Link
The control channel can operate in a low-speed mode
called configuration link in the absence of a clock input.
This allows a microprocessor to program configuration
registers before starting the video link. An internal oscil
-
lator provides the clock for the configuration link. Set
CLINKEN = 1 on the serializer to enable configuration
link. Configuration link is active until the video link is ena
-
bled. The video link overrides the configuration link and
attempts to lock when SEREN = 1.
Table 12. Fast High-Immunity Mode
Requirements
X = Don’t care
Fast high-immunity mode requires DRS = 0.
Table 11. Reverse Control Channel Modes
HIGHIMM BIT OR GPO/
HIM PIN SETTING
REVFAST BIT
REVERSE CONTROL CHANNEL MODE
MAX UART/I
2
C BIT RATE
(kbps)
LOW (1)
X
Legacy reverse control channel mode
(compatible with all GMSL devices)
1000
HIGH (1)
0
High-immunity mode
500
1
Fast high-immunity mode
1000
BWS SETTING
ALLOWED RXCLKIN_
FREQUENCY (MHz)
Low
> 41.66
High
> 30
Open
> 83.33
MAX9277/MAX9281
3.12Gbps GMSL Serializers for Coax or
STP Output Drive and LVDS Input
www.maximintegrated.com
Maxim Integrated │
44