Specifications
2–40 Chapter 2: Board Components
Communication Ports and Interfaces
Cyclone III 3C120 Development Board Reference Manual © March 2009  Altera Corporation
10/100/1000 Ethernet
The 10/100/1000 Ethernet PHY port is provided using a dedicated 10/100/1000 
base-T, auto-negotiating Ethernet PHY with reduced Gigabit media independent 
interface (RGMII) to the FPGA. The target device is the Marvell 88E1111, which uses 
2.5-V and 1.2-V power rails. The Marvell 88E1111 requires a 25-MHz reference clock 
driven from a dedicated oscillator. 
The Marvell device is provided for copper RS-45 Ethernet connectivity and comes in 
the BCC96 leadless chip carrier package. The device interfaces to a HALO 
HFJ11-1G02E model RJ-45.
The PHY device provides 32 internal management registers that can be accessed using 
the Management Interface (MDIO). The MDIO address of the PHY device is 
configured to the value 18 (0x12).
Figure 2–12 shows the interface between the FPGA and the PHY device. 
Ta bl e  2–44 lists the signal name, description, and I/O standard for the Ethernet PHY 
interface I/O. The signal name and type are relative to the Cyclone III device, i.e., the 
I/O setting and direction. 
Figure 2–12.  Interface Between the FPGA and the PHY Device
TXC 
TX_EN 
TD[3:0] 
GTX_CLK 
TX_EN 
TDX[3:0] 
RXC 
RX_DV 
RD[3:0] 
RX_CLK 
RX_DV 
RXD[3:0] 
Cyclone III 
 Device 
 MAC Block 
Marvell 88E111 
RGMII Interface 
 PHY Layer 
Table 2–44.  Ethernet PHY Interface I/O (Part 1 of 2)
Board 
Reference Description I/O Standard
Schematic
Signal Name
Cyclone III
Device Pin 
Number
U5 pin 8 RGMII interface transmit clock 2.5 V ENET_GTX_CLK T8
U5 pin 73 1000 MB link established 2.5 V ENET_LED_LINK1000 AC25
U5 pin 25 Management bus data clock 2.5 V ENET_MDC N8
U5 pin 24 Management bus data 2.5 V ENET_MDIO L5
U5 pin 28 Reset 2.5 V ENET_RESETN AD2
U5 pin 2 RGMII interface receive clock 1.8 V ENET_RX_CLK B14
U5 pin 95 RGMII interface receive data bus bit 0 2.5 V ENET_RX_D0 W8
U5 pin 92 RGMII interface receive data bus bit 1 2.5 V ENET_RX_D1 AA6
U5 pin 93 RGMII interface receive data bus bit 2 2.5 V ENET_RX_D2 W7
U5 pin 91 RGMII interface receive data bus bit 3 2.5 V ENET_RX_D3 Y6
U5 pin 94 RGMII interface receive control 2.5 V ENET_RX_DV AB4
U5 pin 11 RGMII interface transmit data bus bit 0 2.5 V ENET_TX_D0 W4










