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3.6
Low Speed Signals
3.6.1
External HW Control
Low Speed Signals are controllable using an external source, this can be done through J7
and J8 pin headers, for modules A and B, respectively. In this case a jumper should be
placed on pin header P19 (HW_CTRL) shown in the image below.
Figure 4: Hardware Signals
When a jumper is placed on P19 (HW_CTRL), the control signals can be accessed
externally through pin headers shown above. In this case control signals are tri-stated in
the microcontroller and controlled externally by the user.
The low speed signals circuit shown below shows the connection of these signals to the
microcontroller and QSFP-DD connector.
Figure 5: Low Speed Signals Schematics
3.6.2
Pin Access
All QSFP-DD pins are accessible through pin header connectors, including I2C, Control and
Status signals.
