Power management – Altera V-Series Avalon-MM DMA User Manual
Page 30
Parameter
Value
Description
Pending Bit Array
(PBA) Offset
[31:0]
Used as an offset from the address contained in one of the
function’s Base Address registers to point to the base of the
MSI-X PBA. The lower 3 bits of the PBA BIR are set to zero by
software to form a 32-bit qword-aligned offset. This field is
read-only.
PBA BAR Indicator
[2:0]
Specifies the function Base Address registers, located
beginning at 0x10 in Configuration Space, that maps the MSI-
X PBA into memory space. This field is read-only. Legal range
is 0–5.
Related Information
Power Management
Table 3-8: Power Management Parameters
Parameter
Value
Description
Endpoint L0s
acceptable
latency
Maximum of 64 ns
Maximum of 128 ns
Maximum of 256 ns
Maximum of 512 ns
Maximum of 1 us
Maximum of 2 us
Maximum of 4 us
No limit
This design parameter specifies the maximum acceptable
latency that the device can tolerate to exit the L0s state for any
links between the device and the root complex. It sets the
read-only value of the Endpoint L0s acceptable latency field of
the
Device Capabilities Register
(0x084).
This Endpoint does not support the L0s or L1 states. However,
in a switched system there may be 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 64 ns. This is the safest
setting for most designs.
UG-01154
2014.12.18
Power Management
3-9
Parameter Settings
Altera Corporation