MAX9257GTL/V+ Maxim Integrated Products, MAX9257GTL/V+ Datasheet - Page 34

• Manufacturer Part Number: MAX9257GTL/V+
• Description: IC SER/DESER PROG 40TQFN-EP
• Manufacturer: Maxim Integrated Products

Specifications of MAX9257GTL/V+

• Function: Serializer/Deserializer
• Data Rate: 840Mbps
• Input Type: Serial
• Output Type: LVDS
• Number Of Inputs: 16
• Number Of Outputs: 1
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 40-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Fully Programmable Serializer/Deserializer
with UART/I
The UART-to-I
packets issued by the ECU and converts them to an I
master protocol when in base mode. A slave can use an
ACK or NACK to indicate a busy or wait state, but cannot
hold SCL low to indicate a wait state. Multiple slaves are
supported. The UART-to-I
than 22 UART bit times and needs to be taken into
account when setting the ETO and STO timeout periods
for read commands. UART-to-I
standard UART format to standard I
25). This includes data-bit ordering conversion because
UART transmits the LSB in first while I
MSB first. UART/I
times when reading from an I
The MAX9257/MAX9258 store their own 7-bit device
addresses in register REG5. All packets not addressed
to the MAX9257/MAX9258 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 MAX9257 or MAX9258. SDA and SCL
are also idle when the I
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
Figure 24. CTO Timing
34
VSYNC_IN
CONTROL
CHANNEL
SDI/O ±
DOUT_
2
CCEN
C converter. The I
______________________________________________________________________________________
RX
TX
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
C converter accepts UART read or write
T1
2
C read delay is a maximum 34 bit
T2
2
C interfaces (SDA and SCL) are
2
C interface is programmed to
ACTIVITY
ECU
2
C conversion delay is less
2
2
C peripheral.
BYPASS MODE
UART-to-I
C Control Channel
FROZEN
Bypass Mode (Details)
2
C converter converts
2
C format (Figure
2
T4
T3
C transmits the
2
C Converter
HSK
T5
VIDEO
2
C
STO > CTO > ETO
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 MAX9257/MAX9258. Bypass mode
allows only UART programming of peripheral device by
ECU. There is no I
mode is entered by writing a 0 to INTMODE and by writ-
ing a 1 to INTEN (Table 23). Bypass mode disables ECU
programming of the MAX9257/MAX9258 to allow any
UART communication protocol with the peripheral device.
Once bypass mode is entered, the MAX9257/MAX9258
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 (Figure 24). Use this setting to stay in 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 vertical
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 channel,
CTO times out before STO. STO closes the channel
(because ETO is not enabled) if no communication is
VIDEO
T1
BYPASS MODE
2
C connection in bypass mode. Bypass
T3
FROZEN
T2
BASE MODE
HSK
T5
VIDEO