Altera Corporation
Reference Manual
2–13
May 2007
Nios Development Board Stratix II Edition
Board Components
Ethernet
MAC/PHY (U4) &
RJ45 Connector
(RJ1)
The LAN91C111 chip (U4) is a 10/100 Ethernet media access control and
physical interface (MAC/PHY) chip. The control pins of U4 are
connected to the FPGA so that Nios II systems can access Ethernet
networks via the RJ-45 connector (RJ1) as shown in
Figure 2–4
. The
Nios II development tools include hardware and software components
that allow Nios II processor systems to communicate with the
LAN91C111 Ethernet device.
Figure 2–4. Ethernet RJ-45 Connector
Refer to
Table 2–9
for connections between the FPGA and the MAC/PHY
device.
1
The Ethernet MAC/PHY device shares both address and data
connections with the flash memory.
Table 2–9. Ethernet MAC/PHY Pin Table
FPGA Pin
U4 Pin
Pin Function
Board Net Name
(1)
AB25
41
Address Enable
enet_aen
W20
43
Synchronous Ready
enet_srdy_n
W19
40
VL Bus Access
enet_vlbus_n
Y21
45
Local Device
enet_ldev_n
Y20
38
IO Char Ready
enet_iochrdy
AA22
37
Address Strobe
enet_ads_n
AA21
42
Local Bus Clock
enet_lclk
W26
46
Ready/Return
enet_rdyrtn_n
AA26
35
Bus Cycle
enet_cycle_n
AA25
36
Write/Read
enet_w_r_n
W24
34
Bus Chip Select
enet_datacs_n
W23
29
Interrupt
enet_intr0
RJ1
U4