参数资料
型号: MAX9257AGCM/V+
厂商: Maxim Integrated Products
文件页数: 29/53页
文件大小: 0K
描述: IC SERDE PROG UART/I2C 48TQFP
标准包装: 250
系列: *
Maxim Integrated Products 35
MAX9257A/MAX9258A
Fully Programmable Serializer/Deserializer
with UART/I2C Control Channel
PRBS Errors
During the PRBS test, the MAX9258A checks received
PRBS data words by comparing them to internally gener-
ated PRBS data. Detected errors are counted in the PRBS
error register (REG12) in the MAX9258A. Whenever the
number of detected PRBS errors is more than 0, ERROR
asserts low. The PRBS error register is reset when ECU
writes a 0 to PRBSEN register (REG4[0]). In this case,
ERROR deasserts high immediately if PRBS errors were
the only reason that ERROR was asserted low.
Short Synchronization Pattern
The short synchronization pattern is part of the handshak-
ing procedure between the MAX9257A and MAX9258A
after the control channel phase. It is used to resynchro-
nize the MAX9258A’s clock and data recovery circuit
to the MAX9257A before the video phase begins. The
MAX9257A transmits the short synchronization pattern
when it receives the lock frame from the MAX9258A. The
length of short synchronization pattern is dependant on
the PRATE range. When PRATE is 00 or 01, the short
synchronization pattern consists of 546 words and when
PRATE is 10 or 11, the short synchronization pattern con-
sists of 1090 words. Every word is one pixel clock period.
Long Synchronization Pattern
At power-up or when the MAX9257A does not receive a
lock frame from the MAX9258A, the MAX9257A transmits
a long synchronization pattern. The long synchronization
pattern consists of 17,410 words. Every word is one pixel
clock period. When REM is high, if synchronization is not
achieved after 62 attempts, the MAX9257A resets SEREN
to 0 so that the control channel stays open to allow trou-
bleshooting. When REM is low, the MAX9257A/MAX9258A
continuously tries to reestablish the connection.
Lock Verification (Handshaking)
At the end of every vertical blanking time, the MAX9257A
verifies that the MAX9258A did not lose lock. The
MAX9258A handshakes with the MAX9257A to indicate
lock status. The handshaking occurs after the channel
closes (Figures 28 and 23). If the number of decoding
errors in a time window did not exceed a certain thresh-
old during the last video phase, the MAX9258A sends
back the lock frame that indicates lock. If the MAX9257A
receives the lock frame, the MAX9257A transmits a short
synchronization pattern. The MAX9258A features a pro-
prietary VCO mechanism that prevents frequency drift
while in the control channel. This allows for successful
resynchronization after extended use of control chan-
nel. If the number of decoding errors in a time window
exceeds a certain threshold, the MAX9258A loses lock,
LOCK goes low, and the lock frame is not sent. The
MAX9258A also loses lock if handshaking is not suc-
cessful. If the MAX9257A does not receive the lock frame,
it transmits a long synchronization pattern before the start
of next video phase. When REM = 1, if the lock frame
is not received by the MAX9257A after 62 consecutive
attempts to synchronize, SEREN is disabled so that the
control channel opens permanently for troubleshooting.
Link Status (LOCK and CCEN)
The LOCK output indicates whether the MAX9258A is
locked to the MAX9257A. LOCK is an open-drain out-
put that needs to be pulled up to VCC. LOCK asserts
low to indicate that the MAX9258A is not locked to the
MAX9257A and high when it is. In the control channel
phase, LOCK stays high if LOCK is high in the video
phase. While in the control channel phase, the MAX9258A
PLL frequency is held constant, PCLK output is active
and data outputs are frozen at their last valid value before
entering the control channel. CCEN output indicates
whether the devices are in the control channel phase
or video phase. CCEN goes high when the devices are
in the control channel phase (Table 27). Only at initial
power-up, CCEN goes high before communication in the
control channel is ready (see the Link Power-Up section).
Control Channel
Overview of Control Channel Operation
The control channel is used by the ECU to program
registers in the MAX9257A, MAX9258A, and peripheral
devices (such as a camera) during vertical blanking, after
power-up, or when serialization is disabled. Control chan-
nel communication is half-duplex UART. The peripheral
interface on the MAX9257A can be programmed to be I2C
or UART. Operation of the control channel is synchronized
with the VSYNC input after the ECU starts serialization of
video data. Programmable timers, ECU signal activity,
and end frame determine how long the control channel
stays open. The control channel remains open as long
as there is signal activity from the ECU. When the control
channel closes, the LVDS serial link is reestablished.
Table 27. Link Status
LOCK
CCEN
INDICATION
1
0
LVDS channel active
1
Control channel active
0
X
PLL loss of lock
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MAX9257AGTL 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:Fully Programmable Serializer/Deserializer with UART/I2C Control Channel
MAX9257AGTL/V+ 功能描述:串行器/解串器 - Serdes Prog Serializer / Deserializer RoHS:否 制造商:Texas Instruments 类型:Deserializer 数据速率:1.485 Gbit/s 输入类型:ECL/LVDS 输出类型:LVCMOS 输入端数量:1 输出端数量:20 工作电源电压:2.375 V to 2.625 V 工作温度范围:0 C to + 70 C 封装 / 箱体:TQFP-64
MAX9257AGTL/V+T 功能描述:串行器/解串器 - Serdes Prog Serializer / Deserializer RoHS:否 制造商:Texas Instruments 类型:Deserializer 数据速率:1.485 Gbit/s 输入类型:ECL/LVDS 输出类型:LVCMOS 输入端数量:1 输出端数量:20 工作电源电压:2.375 V to 2.625 V 工作温度范围:0 C to + 70 C 封装 / 箱体:TQFP-64
MAX9257AGTL+ 功能描述:串行器/解串器 - Serdes Prog Serializer / Deserializer RoHS:否 制造商:Texas Instruments 类型:Deserializer 数据速率:1.485 Gbit/s 输入类型:ECL/LVDS 输出类型:LVCMOS 输入端数量:1 输出端数量:20 工作电源电压:2.375 V to 2.625 V 工作温度范围:0 C to + 70 C 封装 / 箱体:TQFP-64