41CL Calculator Manual
© 2019 Systemyde International Corporation
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connectors that need to have wires soldered to them.
Solder short (20-30cm should be sufficient) wires to the solder pads labelled VIN, GND
and POR. The RST solder pad is not required for programming.
Battery power is not appropriate from programming. Instead use a benchtop power
supply. The 41CL board requires 5V (4.0v minimum / 6.0V maximum) for programming.
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Make sure the power supply is OFF before connecting it to the 41CL board.
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Connect the GND wire to the ground of a benchtop power supply.
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Connect the VIN wire to the positive output from the power supply.
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Connect the POR wire to the ground of the power supply to program the FPGA or the
Flash. Leave this wire unconnected to program the CPLD. Grounding the POR signal
turns on the switched power supplies on the board.
Do not turn on the power supply until the programming cable is connected. Be aware that
some variable power supplies overshoot quite a bit on start-up. If you are using a variable
supply it is probably better to manually ramp up the supply voltage from zero to the final
value rather than turning on the supply with the full supply voltage selected.
CPLD Programming
The CPLD is programmed using the connector labelled CP on the board. This is the same
connector used for the serial port signals. The CPLD is programmed using a Xilinx
programming cable. The figure below shows the wiring required between the CPLD
connector on the board and the standard Xilinx programming cable.