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Figure 2-1: Clock Manager Block Diagram
SDRAM Clock Group
Clock Manager
Peripheral Clock Group
SDRAM
Controller
Subsystem
MPU, L3, L4
& Debug
PLL-Driven
Peripherals
Peripheral
PLL
f2h_sdram_ref_clk
f2h_periph_ref_clk
FPGA Portion
Control & Status
Registers
L4 Bus (osc1_clk)
HPS_CLK2
HPS_CLK1
Flash Controller Clocks
Flash
Controllers
osc1_clk
OSC1 Clock Group
Main Clock Group
Dividers
Main
PLL
SDRAM
PLL
OSC1-Driven
Peripherals
Divider
Dividers
Control
Logic
reset_manager_safe_mode_req
Reset
Manager
Functional Description of the Clock Manager
Clock Manager Building Blocks
PLLs
The clock manager contains three PLLs: main, peripherals, and SDRAM. These PLLs generate the majority
of clocks in the HPS. There is no phase control between the clocks generated by the three PLLs.
Each PLL has the following features:
• Phase detector and output lock signal generation
• Registers to set VCO frequency
• Multiplier range is 1 to 4096
• Divider range is 1 to 64
• Six post-scale counters (C0-C5) with a range of 1 to 512
• PLL can be enabled to bypass all outputs to the
osc1_clk
clock for glitch-free transitions
Altera Corporation
Clock Manager
2-3
Functional Description of the Clock Manager
cv_54002
2013.12.30