Chapter 2: Board Components
2–19
Clock Circuitry
May 2013
Altera Corporation
Cyclone V GX FPGA Development Board
Reference Manual
Table 2–11
lists the oscillators, its I/O standard, and voltages required for the
development board.
Off-Board Clock Input/Output
The development board has input and output clocks which can be driven onto the
board. The output clocks can be programmed to different levels and I/O standards
according to the FPGA device’s specification.
Table 2–12
lists the clock inputs for the development board.
Table 2–11. On-Board Oscillators
Source
Schematic Signal Name
Frequency
I/O Standard
Cyclone V GX
Pin Number
Application
X4
CLKIN_50_7A
50.000 MHz
Single-Ended
H17
Top edge
CLKIN_50_TOP
K15
X1
CLK_CONFIG
100.000 MHz
2.5V CMOS
—
Fast FPGA configuration
J19
PCIE_REFCLK_P
100.000 MHz
LVDS
W8
PCI Express x4
PCIE_REFCLK_N
W7
U25
CLKIN_BANK3B_125_R_P
125.000 MHz
1.5V LVDS
(fanout
buffer)
Y15
Bottom edge
CLKIN_BANK3B_125_R_N
AA15
CLKIN_BANK4A_125_R_P
AC15
CLKIN_BANK4A_125_R_N
AB16
REFCLK1_Q2L_P
P8
HSMC port A
REFCLK1_Q2L_N
N7
X2
CLK_148_P
148.500 MHz
LVDS
R8
HD-SDI video
CLK_148_N
R7
Table 2–12. Off-Board Clock Inputs
Source
Schematic Signal
Name
I/O Standard
Cyclone V GX
Pin Number
Description
SMA
CLKIN_SMA_P
LVPECL
—
Input to LVDS fan-out buffer (drives one REFCLK)
CLKIN_SMA_N
LVPECL
—
Samtec HSMC
HSMA_CLK_IN0
2.5-V
L15
Single-ended input from the installed HSMC cable
or board.
Samtec HSMC
HSMA_CLK_IN_P1
LVDS/2.5-V
H19
LVDS input from the installed HSMC cable or
board. Can also support 2x LVTTL inputs.
HSMA_CLK_IN_N1
LVDS/LVTTL
J18
Samtec HSMC
HSMA_CLK_IN_P2
LVDS/LVTTL
L14
LVDS input from the installed HSMC cable or
board. Can also support 2x LVTTL inputs.
HSMA_CLK_IN_N2
LVDS/LVTTL
L13
PCI Express
Edge
PCIE_REFCLK_P
LVDS
W8
LVDS input from the PCI Express edge connector.
PCIE_REFCLK_N
HCSL
W7