Vendor specific extended capability (vsec), Phy characteristics – Altera Stratix V Avalon-ST User Manual
Page 52

Vendor Specific Extended Capability (VSEC)
Table 4-11: VSEC
Parameter
Value
Description
User ID register
from the Vendor
Sepcific Extended
Capability
Custom value
Sets the read-only value of the 16-bit User ID register from the
Vendor Specific Extended Capability. This parameter is only
valid for Endpoints.
PHY Characteristics
Table 4-12: PHY Characteristics
Parameter
Value
Description
Gen2 transmit
deemphasis
3.5dB
6dB
Specifies the transmit de-emphasis for Gen2. Altera
recommends the following settings:
• 3.5dB: Short PCB traces
• 6.0dB: Long PCB traces.
Use ATX PLL
On/Off
When enabled, the Hard IP for PCI Express uses the ATX PLL
instead of the CMU PLL Using the ATX PLL instead of the
CMU PLL reduces the number of transceiver channels that are
necessary for Gen1 and Gen2 variants. This option requires
the use of the soft reset controller and does not support the
CvP flow. For more information about channel placement,
refer to
Enable Common
Clock Configura‐
tion (for lower
latency)
On/Off
When you turn this option on, the Application Layer and
Transaction Layer use a common clock. Using a common
clock reduces datapath latency because synchronizers are not
necessary.
This parameter is only available for the Avalon-ST interface.
UG-01097_avst
2014.08.18
Vendor Specific Extended Capability (VSEC)
4-15
Parameter Settings
Altera Corporation