Chapter 2: Board Components
2–25
Components and Interfaces
May 2013
Altera Corporation
Cyclone V GX FPGA Development Board
Reference Manual
Figure 2–6
shows the PCI Express reference clock levels.
The JTAG and SMB are optional signals in the PCI Express specification. Both types of
signals are wired to the Cyclone V GX but are not required for normal operation.
Table 2–22
summarizes the PCI Express pin assignments. The signal names and
directions are relative to the Cyclone V GX.
Figure 2–6. PCI Express Reference Clock Levels
V
MAX
= 1.15 V
V
CROSS MAX
= 550 mV
V
CROSS MIN
= 250 mV
V
MIN
= –0.30 V
REFCLK –
Table 2–22. PCI Express Pin Assignments, Schematic Signal Names, and Functions
Board
Reference (J19)
Schematic Signal Name
Cyclone V GX
Pin Number
I/O Standard
Description
A5
PCIE_JTAG_TCK
—
LVTTL
JTAG chain clock
A6
PCIE_JTAG_TDI
—
LVTTL
JTAG chain data in
A7
PCIE_JTAG_TDO
—
LVTTL
JTAG chain data out
A8
PCIE_JTAG_TMS
—
LVTTL
JTAG chain mode select
A11
PCIE_PERSTN
W27
LVTTL
Reset
A1
PCIE_PRSNT1N
—
LVTTL
Link width DIP switch
B17
PCIE_PRSNT2N_X1
—
LVTTL
Hot plug present detect
B31
PCIE_PRSNT2N_X4
—
LVTTL
Hot plug present detect
A13
PCIE_REFCLK_P
W8
HCSL
Reference clock input
A14
PCIE_REFCLK_N
W7
HCSL
Reference clock input
B14
PCIE_RX_P0
AG2
1.5-V PCML
Receive bus
B15
PCIE_RX_N0
AG1
1.5-V PCML
Receive bus
B19
PCIE_RX_P1
AE2
1.5-V PCML
Receive bus
B20
PCIE_RX_N1
AE1
1.5-V PCML
Receive bus
B23
PCIE_RX_P2
AC2
1.5-V PCML
Receive bus
B24
PCIE_RX_N2
AC1
1.5-V PCML
Receive bus
B27
PCIE_RX_P3
AA2
1.5-V PCML
Receive bus
B28
PCIE_RX_N3
AA1
1.5-V PCML
Receive bus
B5
PCIE_SMBCLK
R11
2.5-V
SMB clock
B6
PCIE_SMBDAT
V22
2.5-V
SMB data
A16
PCIE_TX_P0
AF4
1.5-V PCML
Transmit bus
A17
PCIE_TX_N0
AF3
1.5-V PCML
Transmit bus
A21
PCIE_TX_P1
AD4
1.5-V PCML
Transmit bus
A22
PCIE_TX_N1
AD3
1.5-V PCML
Transmit bus