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Getting Started with the IGLOO PLUS Starter Kit Demo Design
IGLOO PLUS Starter Kit User’s Guide 53
When HOLD is disabled at the output buffer, the output will depend on the resister pull-up or pull-down direction in
Flash*Freeze mode. If HOLD is enabled at the output buffer, then the output will depend on the state right before
entering Flash*Freeze mode.
1. Similar to Demo 1, before starting Demo 4, check the jumper settings and set all switches to the OFF or CLOSED
position. Ensure the F*F switch is in the OFF position.
2. Power-on the IGLOO PLUS Starter Kit board using the power supply or USB cable included in the starter kit.
3. Press and release the System Reset button (SW7) to reset the IGLOO PLUS FPGA.
• Observe that LED D1 is ON during Reset.
4. Example A: Set both FET Switches [2:1] to the CLOSE position.
• Based on the logic in this demo design, both P-Type FET LEDs D13 and D14 should be ON and N-Type FET
LED D15 should be OFF. Refer to the board schematic for reference on the FET LED connections.
• Enable Flash*Freeze mode by setting the F*F Switch to ON.
After entering Flash*Freeze mode, observe that P-Type FET LED D13 stays ON because the HOLD state for
this output configuration was enabled.
Also observe that P-Type FET LED D14 is ON due to the pull-down resister configuration.
N-Type FET LED D15 turns ON due to the pull-up resister configuration.
Toggle the FET Switches back and forth.
Observe that the LEDs are unaffected, because the device is in Flash*Freeze mode. The inputs are not able
to pass data into the device.
Return the FET Switches [2:1] back to the CLOSE position
• Disable Flash*Freeze mode by setting the F*F Switch to OFF.
After exiting the Flash*Freeze mode, observe that N-Type FET LED D15 turns OFF.
5. Example B: Set both FET Switches [2:1] to the OPEN position
• Based on the logic in this demo design, both P-type FET LEDs D13 and D14 should be OFF and N-type FET
LED D15 should be ON.
• Enable Flash*Freeze mode by setting the F*F Switch to ON.
After entering Flash*Freeze mode, observe that P-Type FET LED D13 remains OFF because the HOLD state
for this output configuration was enabled.
Also observe that P-Type FET LED D14 turns ON due to the pull-down resister configuration.
N-Type FET LED D15 is ON due to the pull-up resister configuration.
• Disable Flash*Freeze mode by setting the F*F to OFF.
After exiting the Flash*Freeze mode, observe that P-Type FET LED D14 turns OFF.
Table 6-3 · FET Output Configuration in Demo Design
FET LED I/O Hold
Internal Weak
Resister Pull
Description
FET LED D13 Enabled Down P-Type
FET LED D14 Disabled Down P-Type
FET LED D15 Disabled Up N-Type
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