Will a HCMOS output TCXO work with LPC1114?
"HCMOS output" implies that a low level will be no more than 0.3Vcc, and that a high level will be no less than 0.7Vcc. This is compatible with any CMOS input with a supply of Vcc, and if Vcc is 3.3V or higher then also with any TTL or LVTTL input.

All crystal oscillators (but not bare crystals) generate square waves; for rise and fall times and duty cycle check the datasheet.