Datasheet

UART Never Come Back Operation
This operation is used in an application when the
ECU completes the configuration of the MAX9257A/
MAX9258A right after power-up and does not want to
access the MAX9257A/MAX9258A once the video
transmission begins. The following procedure is an
example of one of many possible configurations:
1) Start the program or press the Reset the EVKIT
button on the ECU Control tab sheet (Figure 3).
2) If MAX9257A REM is set to high (JU25 shunt is set
across pins 1-2), press the ECU Wakes Up
MAX9257A button on the ECU Control tab sheet. If
MAX9257A REM is set to low (JU25 shunt is set
across pins 2-3), skip this step.
3) Navigate to the Deserializer MAX9258A tab sheet
(Figure 4). Press the Read MAX9258A & 9257A
button to refresh the current register values on the
GUI.
4) Keep the four Write Both 9258A&9257A checkbox-
es checked.
5) Set t
STO
and t
ETO
on both the MAX9258A and
MAX9257A to expected values. Note that the t
STO
and t
ETO
times are based on the pixel clock
(PCLK_IN) time. For example, if PCLK_IN is 30MHz,
set STODIV to 1024 and STOCNT to 0, t
STO
=
(1024 x 1/30)µs ≈ 34µs. Set ETODIV to 1024 and
ETOCNT to 4, t
ETO
= (1024 x 5/30)µs ≈ 170µs.
6) Set other MAX9258A registers as desired.
Evaluates: MAX9257A/MAX9258A
MAX9257A/MAX9258A Evaluation Kit
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Figure 5. MAX9257A/MAX9258A Evaluation Kit Software—Serializer MAX9257A Tab