P5_1 is for input of an external oscillator, not only a crystal. I think this is just a naming difference, is it?
When you did not additionally provide the 24MHz crystal your system will not run in this configuration.
What is the exact device number you're using?
CY8C4247LQ-BL483 and CY8C4248LQ-BL583
There 24MHz onboard, and running well using this 24MHz.
Yes, it is a TCXO with VDD 1ppm oscillator.
I would try to boot using IMO and then switch to external clock with CySysClkWriteHfclkDirect() API (see "System Reference Guide")
Thanks, after using this method it works.
And in the system reference guide, it said PSOC4 can't boot with external clk, I just didn't notice this.