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2–20
Chapter 2: Board Components
Clock Circuitry
Cyclone V GT FPGA Development Board
August 2017
Altera Corporation
Reference Manual
Figure 2–5
shows the default frequencies of all external clocks going to the
Cyclone V GT FPGA on the development board.
Table 2–11
lists the oscillators, its I/O standard, and voltages required for the
development board.
Figure 2–5. Cyclone V GT FPGA Development Board Clocks
Reference
Clock Input
SMA
50 MHz
Si570
100 MHz
Default
QL2
QL1
QL0
B8
B7
B3
B4
B6
B5
U13
Output
SMA
SMA
CLK10
CLKINTOP_P/N
CLK5
CLK_125M_P/N
CLK6
CLKINA_50
CLK7
CLKIN_R_P/N
50 MHz
REFCLK_QL3_P/N
(HSMB)
REFCLK_QL1_P/N
(PCIe)
PCIE_REFCLK_P/N
CLK2
CLKINBOT_P/N
Buffer
100 MHz
Default
SMA
125 M
Buffer
50 MHz
50 MHz
CLKIN_MAX_50
Si571
148.5 MHz
Default
SDI
(148.5 M, 148.35 M)
REFCLK_QL2_P/N
(SDI, HSMA)
U52
J3
J6
J4
J7
U3
X4
X5
X6
X3
Table 2–11. On-Board Oscillators (Part 1 of 2)
Source
Schematic Signal
Name
Frequency
I/O Standard
Cyclone V GT
Pin Number
Application
X6
CLKIN_50
50.000 MHz
1.5-V CMOS
V28
FPGA bank 5B (CLK6p) for
general purpose logic
CLKIN_MAX_50
—
FPGA bank 5B (CLK6p) for
general purpose logic in the
MAX V CPLD
X5
CLK_125M_P
125.000 MHz
LVDS
U31
FPGA bank 6A (CLK5p)
CLK_125M_N
U30
FPGA bank 6A (CLK5n)