When asserted the "Reset" pin is hardware reset for the chip. There is no way to keep the "CLK output" running during the power-up sequence of the device. The internal PLL stabilizes approximately 200 us after VCC has reached 3.3V (CY7C68000 Datasheet, Page 5 of 17, section 3.4). When using a crystal, the minimum reset time (tRESET) is 1.9 ms. (CY7C68000 Datasheet, page 12 of 17, Table 8-1). TX2 is currently obsolete, the functional replacement is TX2UL. All the related collaterals of TX2UL can be found in the link here.