Mike,
Attached is a sample and SIMPLE project that outputs the ECO frequency directly to a GPIO pin.
Tip: Never directly measure ECO pins connected to the crystal. ANY probe capacitance will adversely effect the frequency and in some cases the stability of the oscillation. It is always preferable to push the crystal output through a buffer or other frequency divider.
Any probe capacitance on the output of a buffered output will not affect the crystal frequency.
Using a scope to directly measure the signals on the ECO pins are only useful to verify the crystal is oscillating. This is a GO/NOGO test.
The project I attaches is VERY SIMPLE. This project has no running code in main(). Everything is set up to run before entering main().
It sets up the ECO and routes it to Routed1 path. Then I attach a GPIO pin to Routed1. It's that simple.
I don't have the CY8C4128LQI-BL483 to test this project but it is SO SIMPLE and obvious.
If you have any issues, let me know.
One additional note:
If you are using this in a commercial product, most crystal suppliers will "trim" your ECO design. You give a 'final' PCB with your best guess at the trim caps to the crystal supplier of your target crystal. Make sure there is FW working enabling the ECO 100% of the time. They will use their equipment to measure and, if needed, suggest other trim values to obtain the target frequency and stability.
We do this in automotive to make sure the crystal keeps the target frequency with manufacturer tolerance and stability over the operational temperature range.
