KSZ8775CLX TABLE 2-1: SIGNALS (CONTINUED) Num Pins Pin Name 30 TXC4/REFCLKI4 Type I/O Port Pin Description 4 Port 4 Switch MAC4 SW4-RMII Reference Clock Input RMII: Input for receiving 50 MHz clock in normal mode. 31 RXC4 I/O 4 Port 4 Switch MAC4 SW4-RMII reference clock out: RMII: Output 50 MHz reference clock for the receiving/transmit in the clock mode. 32 TXEN5/ TXD5_CTL IPD 5 MII/RMII: Port 5 switch transmit enable. RGMII: Transmit data control. 33 TXD5_0 IPD 5 RGMII/MII/RMII: Port 5 switch transmit bit [0]. 34 TXD5_1 IPD 5 RGMII/MII/RMII: Port 5 switch transmit bit [1]. 35 GNDD GND 36 VDDIO P 37 38 TXD5_2 TXD5_3 IPD IPD 39 TXER5 IPD 40 NC NC 41 GNDD GND 42 RXD4_1 IPD/O DS00002129C-page 8 Digital ground. 3.3V, 2.5V, or 1.8V digital VDD for digital I/O circuitry. 5 RGMII/MII: Port 5 switch transmit bit [2]. RMII: No connection. 5 RGMII/MII: Port 5 switch transmit bit [3]. RMII: No connection. 5 MII: Port 5 switch transmit error. RGMII/RMII: No connection. No connect Digital ground 4 RMII: Port 4 SW4-RMII receive bit [1] 2015 Microchip Technology Inc.