MAX9249GCM/V+T Maxim Integrated Products, MAX9249GCM/V+T Datasheet - Page 20

• Manufacturer Part Number: MAX9249GCM/V+T
• Description: IC SERIALIZER GMSL LVDS 48TQFP
• Manufacturer: Maxim Integrated Products

Specifications of MAX9249GCM/V+T

• Function: Serializer
• Data Rate: 2.5Gbs
• Input Type: LVDS
• Output Type: Serial
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 48-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Number Of Outputs: -
• Number Of Inputs: -

Gigabit Multimedia Serial Link
Serializer with LVDS System Interface
UART protocol. The FC can also program the peripher-
als on the remote side by sending the UART packets
to the MAX9249 or GMSL deserializer, with the UART
packets converted to I
side of the link (GMSL deserializer for LCD or MAX9249
for image-sensing applications). The FC communicates
with a UART peripheral in base mode (through INTTYPE
register settings), using the half-duplex default GMSL
UART protocol of the MAX9249/GMSL deserializer. The
device addresses of the MAX9249 and GMSL deserial-
izer in base mode are programmable. The default values
are 0x80 for the MAX9249 and 0x90 for the GMSL dese-
rializer.
In base mode, when the peripheral interface uses
I
packets to I
from those of the MAX9249 or GMSL deserializer. The
converted I
bit rate.
In bypass mode, the MAX9249/GMSL deserializer ignore
UART commands from the FC and the FC communi-
cates with the peripherals directly using its own defined
UART protocol. The FC cannot access the MAX9249/
GMSL deserializer’s registers in this mode. Peripherals
accessed through the forward control channel using the
UART interface need to handle at least one RXCLKIN_
period of jitter due to the asynchronous sampling of the
UART signal by RXCLKIN_.
The MAX9249 embeds control signals going to the GMSL
deserializer in the high-speed forward link. Do not send
a logic-low value longer than 100Fs in either base or
bypass mode. The GMSL deserializer uses a proprietary
differential line coding to send signals back towards the
MAX9249. The speed of the control channel ranges from
100kbps to 1Mbps in both directions. The MAX9249/
GMSL deserializer automatically detect the control chan-
nel bit rate in base mode. Packet bit rates can vary up
to 3.5x from the previous bit rate (see the Changing the
Clock Frequency section). Figure 17 shows the UART
protocol for writing and reading in base mode between
the FC and the MAX9249/GMSL deserializer.
Figure 18 shows the UART data format. Even parity is
used. Figures 19 and 20 detail the formats of the SYNC
byte (0x79) and the ACK byte (0xC3). The FC and the
connected slave chip generate the SYNC byte and ACK
byte, respectively. Events such as device wake-up and
interrupt generate transitions on the control channel
that should be ignored by the FC. Data written to the
MAX9249/GMSL deserializer registers does not take
20
2
C (default), the MAX9249/GMSL deserializer convert
_____________________________________________________________________________________
2
C bit rate is the same as the original UART
2
C that have device addresses different
2
C by the device on the remote
effect until after the acknowledge byte is sent. This
allows the FC to verify write commands received without
error, even if the result of the write command directly
affects the serial link. The slave uses the SYNC byte to
synchronize with the host UART data rate automatically.
If the INT or MS inputs of the GMSL deserializer toggles
while there is control-channel communication, the con-
trol-channel communication may be corrupted. In the
event of a missed acknowledge, the FC should assume
there was an error in the packet when the slave device
receives it, or that an error occurred during the response
from the slave device. In base mode, the FC must keep
the UART Tx/Rx lines high for 16 bit times before starting
to send a new packet.
As shown in Figure 21, the remote-side device converts
the packets going to or coming from the peripherals from
the UART format to the I
remote device removes the byte number count and adds
or receives the ACK between the data bytes of I
I
The MAX9249 and GMSL deserializer UART-to-I
version interfaces with devices that do not require regis-
ter addresses, such as the MAX7324 GPIO expander. In
this mode, the I
byte and directly reads/writes the subsequent data bytes
(Figure 22). Change the communication method of the
I
sets command-byte-only mode, while I2CMETHOD = 0
sets normal mode where the first byte in the data stream
is the register address.
The INT pin of the MAX9249 is the interrupt output and
the INT pin of the GMSL deserializer is the interrupt
input. The interrupt output on the MAX9249 follows the
transitions at the interrupt input. This interrupt function
supports remote-side functions such as touch-screen
peripherals, remote power-up, or remote monitoring.
Interrupts that occur during periods where the reverse
control channel is disabled, such as link startup/shut-
down, are automatically resent once the reverse control
channel becomes available again. Bit D4 of register
0x06 in the GMSL deserializer also stores the interrupt
input state. The INT output of the MAX9249 is low after
power-up. In addition, the FC can set the INT output of
MAX9249 by writing to the SETINT register bit. In normal
operation, the state of the interrupt output changes when
the interrupt input on the GMSL deserializer toggles.
2
2
C’s data rate is the same as the UART data rate.
C master using the I2CMETHOD bit. I2CMETHOD = 1
Interfacing Command-Byte-Only
2
C master ignores the register address
2
C format and vice versa. The
Interrupt Control
I
2
C Devices
2
2
C con-
C. The