Refer to the PDF data sheet for device specific package drawings
The main reference clock REF_CLK (RMII_50MHZ_CLK) of RMII interface is internally supplied from PRCM. The source of this clock could be either externally sourced from the RMII_MHZ_50_CLK pin of the device or internally generated from DPLL_GMAC output clock GMAC_RMII_HS_CLK. Please see the PRCM chapter of the device TRM for full details about RMII reference clock.
The I/O Timings provided in this section are valid only for some GMAC usage modes when the corresponding Virtual I/O Timings or Manual I/O Timings are configured as described in the tables found in this section.