The ECOs are oscillator circuits needing an external crystal. Thats what the configuration is for. Your MEMS oscillators are an standalone component. So you need to configure PSoC for just using an external clock signal. I know that its possible for the MHz ECO, but I'm not so sure about the kHz ECO (and I lack the time now to check). Just look in the clock configuration screen...
You might contact max (author of ap notes) directly, and post back here for the
rest of the forum.
Neither ap note discusses if ECO amp is a standard logic inverter or a specific amp
design, so anwering R-R question (my guess is Vssd to Vddd) would be just that, a
guess, and should not be considered sufficient.
You might suggest max rev his ap note(s) to include the basic questions you are asking.
To elaborate a little bit deeper:
- the clock configuration allows only to feed an external clock for the IMO, but not for the ILO
- the external clock signal is routed through the DSI (digital signal interconnect), so it is a normal external signal
- that means the external oscillator needs to supply a logic-level signal (CMOS or TTL)
- it might be possible to just connect your oscillators to the XI inputs of the oscillators, and leave the XO pins open
- should work, but the TRM doesn't say anything about it (though AN54439 does)
- input signals are still subject to maximum ratings (they are normal GPIOs when not used, so input voltage ashould be in 0V - Vdd), and I guess using a digital signal works best
For the 32 Khz, you will be coming thru the internal route to the
amp designed for oscillation, if its not a standard CMOS inverter
like used in GPIO structures, its levels/bias may need to be addressed,
need to be confirmed with max.
I will email max and point him to this thread, and see what we get.
I haven't heard anything from Max. I'll go create a support case.
I have not heard either, glad you posted a CASE, maybe I should have done that from the
getgo as we never know if author still with company.
Here's the response to my case. Looks like, I'm good to go.
MHz XTAL pins are also GPIOs. Hence they can be used as normal GPIOs. Disable the ECO in the .cydwr -> clock tree and select the Digital Signal and source the other clocks from Digital clock. The procedure is same as in the AN60631.
If the peak to peak amplitude of the MEMS oscillator is 3.3 V or more, it should work because internally the signal gets into the clock tree where a level shift will reduced it to 1.8 V peak to peak.
For KHz ECO, you need to enable the KHZ ECO in the clock tree and just connect the external MEMS oscillator to the KHz ECO input. No setting is required for this in Creator.
So summary is MHz ECO needs to be disabled and the same input pin can be used to give external digital clock. But KHz ECO needs to be enabled and connect external clock to the input pin of KHz ECO in PSoC.
I tested both of the clocks int the above mentioned configuration and found it to be working.
Thanks for the Feedback! Hope you are sucessful...