MAX9257AGCM+ Maxim Integrated, MAX9257AGCM+ Datasheet - Page 37

• Manufacturer Part Number: MAX9257AGCM+
• Description: Serializers & Deserializers - Serdes Prog Serializer / Deserializer
• Manufacturer: Maxim Integrated
• Type: Serializerr

Specifications of MAX9257AGCM+

• Rohs: yes
• Data Rate: 840 Mbit/s
• Input Type: LVCMOS
• Output Type: LVDS
• Number Of Inputs: 18
• Number Of Outputs: 1
• Operating Supply Voltage: 1.7 V to 3.6 V
• Operating Temperature Range: - 40 C to + 105 C
• Package / Case: LQFP-48
• Maximum Operating Temperature: + 105 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Supply Voltage - Max: 3.6 V
• Supply Voltage - Min: 1.71 V, 3 V

includes data-bit ordering conversion because UART
transmits the LSB in first while I
UART/I
reading from an I
The devices store their own 7-bit device addresses
in register REG5. All packets not addressed to the
MAX9257A/MAX9258A are forwarded to the UART to-
I
open drain and actively drive a low state. When idle,
SDA and SCL are high impedance and pulled high by a
pullup resistor. SDA and SCL are idle when packets are
addressed to the MAX9257A or MAX9258A. SDA and
SCL are also idle when the I
to be disabled.
In bypass mode, ECU activity and UART communica tion
from the camera reset the ETO and CTO timers. This
allows the control channel to stay in bypass as long as
there is camera activity. In base mode, only ECU activity
resets the ETO and CTO timers.
Bypass mode temporarily or permanently blocks pro-
gramming of the devices. Bypass mode allows only UART
programming of peripheral device by ECU. There is no
I
by writing a 0 to INTMODE and by writ ing a 1 to INTEN
(Table
the devices to allow any UART communication protocol
Figure 24. CTO Timing
2
2
C converter. The I
C connection in bypass mode. Bypass mode is entered
VSYNC_IN
CONTROL
CHANNEL
DOUT_
SDI/O
CCEN
2
23). Bypass mode disables ECU programming of
TX
RX
C read delay is a maximum 34 bit times when
T1 = TIME TO ENTER CONTROL CHANNEL
T2 = STO TIMER
T3 = CTO TIMER
T4 = ETO TIMER
T5 = CONTROL CHANNEL EXIT TIME
HSK = HANDSHAKING BETWEEN THE MAX9257 & THE MAX9258
= TIMER RESET
VIDEO
2
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T1
C peripheral.
Fully Programmable Serializer/Deserializer
2
C interfaces (SDA and SCL) are
T2
ACTIVITY
ECU
2
C interface is programmed
2
BYPASS MODE
C transmits the MSB first.
Bypass Mode (Details)
FROZEN
T4
T3
with UART/I
HSK
T5
VIDEO
STO > CTO > ETO
with the peripheral device. Once bypass mode is entered,
the devices stay in bypass mode until CTO times out.
In bypass mode, the STO and ETO timers determine the
control channel duration. CTO timer determines whether to
revert back to base mode or not, and EF is not recognized.
A useful setting in bypass mode is to set STO > CTO >
ETO because this setting is an alternative to permanent
bypass
mode to avoid the overhead of entering from base mode
every time the control channel opens. If the ECU uses
the channel within a CTO timeout, ETO is activated and
then ETO times out before CTO. The channel closes
because ETO times out, but channel stays in bypass
mode because CTO does not time out. At the next verti-
cal blanking time, bypass mode continues with CTO
reset and the ECU can immediately send commands to
the camera. If the ECU or camera does not use the chan-
nel, CTO times out before STO. STO closes the channel
(because ETO is not enabled) if no communication is
sent, but since CTO timed out, bypass mode ends and
base mode is active for the next vertical blanking period.
With STO > CTO > ETO, bypass mode can be made
continuous by having the ECU send real commands or
dummy commands (such as a command to a nonexist ing
address) each time the control channel opens. Then the
ECU does not have to send a command to enter bypass
mode each time it wants to program the peripheral device.
MAX9257A/MAX9258A
VIDEO
(Figure
T1
2
C Control Channel
BYPASS MODE
24). Use this setting to stay in bypass
T3
FROZEN
T2
BASE MODE
HSK
T5
VIDEO