Vendor specific extended capability (vsec), Phy characteristics, Vendor specific extended capability (vsec) -15 – Altera Arria 10 Avalon-ST User Manual
Page 58: Phy characteristics -15

Parameter
Value
Description
Endpoint L1
acceptable
latency
Maximum of 1 us
Maximum of 2 us
Maximum of 4 us
Maximum of 8 us
Maximum of 16 us
Maximum of 32 us
No limit
This value indicates the acceptable latency that an Endpoint
can withstand in the transition from the L1 to L0 state. It is an
indirect measure of the Endpoint’s internal buffering. It sets
the read-only value of the Endpoint L1 acceptable latency field
of the
Device Capabilities Register
.
This Endpoint does not support the L0s or L1 states. However,
a switched system may include links connected to switches
that have L0s and L1 enabled. This parameter is set to allow
system configuration software to read the acceptable latencies
for all devices in the system and the exit latencies for each link
to determine which links can enable Active State Power
Management (ASPM). This setting is disabled for Root Ports.
The default value of this parameter is 1 µs. This is the safest
setting for most designs.
Vendor Specific Extended Capability (VSEC)
Table 4-12: 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 4-13: 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.
UG-01145_avst
2014.08.18
Vendor Specific Extended Capability (VSEC)
4-15
Parameter Settings
Altera Corporation