LPC54618J512 RMII Interface

[andrew_sig]

Hi! I'm trying to implement Ethernet communication between an LCP54618J512 and a LAN8720 module [https://www.ebay.com/itm/233331877929].
I previously tested with the LPCXpresso development board, which uses a 25 MHz XTAL, and everything works perfectly. I also tested with the LAN8720 module and an ESP32, overriding the 50 MHz clock output and generating the required 50 MHz signal in RMII mode using an ESP32 terminal.
Is it possible to use an LPC54618 terminal to generate the 50 MHz signal? The terminals I'm currently using are:

LAN8720	PHY (RMII)	LPC54618
TXD0	ENET_TXD0	PIO4_19 (14)
TXD1	ENET_TXD1	PIO4_20 (18)
TX_EN	ENET_TX_EN	PIO4_27 (85)
RXD0	ENET_RXD0	PIO4_23 (42)
RXD1	ENET_RXD1	PIO4_24 (67)
CRS_DV	ENET_RX_DV	PIO5_1 (126)
MDC	ENET_MDC	PIO5_3 (129)
MDIO	ENET_MDIO	PIO5_4 (135)
nINT/RETCLK	RMII_REF_CLK	PIO4_14 (194)
nRST	Reset PHY (optional)	PIO4_16 (203)

If I need to use the 50 MHz generated from the LAN8720 module clock, is there any sample code I can use?
Thanks'

[andrew_sig]

Hi! Thanks for your response. I believe PIO3_12 can be used as indicated in the LPCXpresso 54608 user manual.
I'll try a code implementation using MCUXpresso Config Tool, and see what results it gives

[Harry_Zhang · Accepted solution]

Hi @andrew_sig 

Is it possible to use an LPC54618 terminal to generate the 50 MHz signal?

I think yes, you are correct: the P3_12 pin (CLKOUT) can be configured to output a clock signal, and it can be used to provide a 50 MHz reference clock to the LAN8720 PHY for RMII operation.

Is there any sample code I can use?

Currently, there is no related sample code.

BR

Harry