EP2AGX95EF29C6N Datasheet, PDF (128/380 Pages) Altera Corporation – Device Interfaces and Integration

5–20
Chapter 5: Clock Networks and PLLs in Arria II Devices
Clock Networks in Arria II Devices
f For more information about the clock control block and its supported features in the
Quartus II software, refer to the Clock Control Block (ALTCLKCTRL) Megafunction User
Guide.
Figure 5–18. Clock Input Multiplexer Logic for Arria II GX PLLs
CLK[n+3..n] (2)
4
GCLK / RCLK input (3)
(1)
inclk0
Adjacent PLL output
To the clock
switchover block
(1)
4
inclk1
Notes to Figure 5–18:
(1) Input clock multiplexing is controlled through a configuration file (.sof or .pof) only; it cannot be dynamically controlled when the device is
operating in user mode.
(2) Dedicated clock input pins to the PLLs: n = 4 for PLL_4; n = 4 or 8 for PLL_3; n = 8 or 12 for PLL_2; and n = 12 for PLL_1.
(3) You can drive the GCLK or RCLK clock input with an output from another PLL, a pin-driven GCLK or RCLK, or through a clock control block,
provided the clock control block is fed by an output from another PLL or a pin-driven dedicated GCLK or RCLK. An internally generated global
signal or general purpose I/O pin cannot drive the PLL.
Figure 5–19. Clock Input Multiplexer Logic for Arria II GZ devices
clk[n+3..n] (2)
4
GCLK / RCLK input (3)
(1)
inclk0
Adjacent PLL output
To the clock
switchover block
(1)
4
inclk1
Notes to Figure 5–19:
(1) When the device is operating in user mode, input clock multiplexing is controlled through a configuration file (.sof or .pof) only and cannot be
dynamically controlled.
(2) n = 0 for L2 and L3 PLLs; n = 4 for B1 and B2 PLLs; n = 8 for R2 and R3 PLLs, and n = 12 for T1 and T2 PLLs.
(3) You can drive the GCLK or RCLK input using an output from another PLL, a pin-driven GCLK or RCLK, or through a clock control block provided
the clock control block is fed by an output from another PLL or a pin-driven dedicated GCLK or RCLK. An internally generated global signal or
general purpose I/O pin cannot drive the PLL.
Arria II Device Handbook Volume 1: Device Interfaces and Integration
July 2012 Altera Corporation