Chapter 5: Clock Networks and PLLs in Arria II Devices
5–9
Clock Networks in Arria II Devices
December 2010
Altera Corporation
Arria II Device Handbook Volume 1: Device Interfaces and Integration
Dedicated Clock Inputs Pins
CLK pins can either be differential clocks or single-ended clocks. Arria II GX devices
support six differential clock inputs or 12 single-ended clock inputs, while Arria II GZ
devices support 16 differential clock inputs or 32 single-ended clock inputs. You can
also use the dedicated clock input pins
CLK[4..15]
(for Arria II GX devices) and
CLK[15..0]
(for Arria II GZ devices) for high fan-out control signals such as
asynchronous clears, presets, and clock enables for protocol signals such as
TRDY
and
IRDY
for PCI Express
®
(PCIe
®
) through GCLK or RCLK networks.
Logic Array Blocks
You can drive up to four signals into each GCLK and RCLK network with logic array
block (LAB)-routing to allow internal logic to drive a high fan-out, low-skew signal.
1
You cannot drive Arria II PLLs by internally generated GCLKs or RCLKs. The input
clock to the PLL has to come from dedicated clock input pins or PLL-fed
GCLKs/RCLKs only.
PLL Clock Outputs
and
list the connection between the dedicated clock input pins
and GCLKs.
Table 5–2. Clock Input Pin Connectivity to GCLK Networks for Arria II GX Devices
Clock Resources
CLK (p/n Pins)
4
5
6
7
8
9
10
11
12
13
14
15
GCLK[0..3]
—
—
—
—
—
—
—
—
—
—
—
—
GCLK[4..7]
v
v
v
v
—
—
—
—
—
—
—
—
GCLK[8..11]
—
—
—
—
v
v
v
v
—
—
—
—
GCLK[12..15]
—
—
—
—
—
—
—
—
v
v
v
v
Note to
(1)
GCLK[0..3]
is not driven by any clock pins because there are no dedicated clock pins on the left side of the Arria II GX device.
Table 5–3. Clock Input Pin Connectivity to the GCLK Networks for Arria II GZ Devices
Clock Resources
CLK (p/n Pins)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
GCLK[0..3]
v v v v
—
—
—
—
—
—
—
—
—
—
—
—
GCLK[4..7]
—
—
—
—
v v v v
—
—
—
—
—
—
—
—
GCLK[8..11]
—
—
—
—
—
—
—
—
v v v v
—
—
—
—
GCLK[12..15]
—
—
—
—
—
—
—
—
—
—
—
—
v v v v