Device Capabilities
Table 4-6: Capabilities Registers
Parameter
Possible Values
Default Value
Description
Maximum
payload size
128 bytes
256 bytes
512 bytes
1024 bytes
2048 bytes
128 bytes
Specifies the maximum payload size supported. This
parameter sets the read-only value of the max payload
size supported field of the Device Capabilities register
(0x084[2:0]). Address: 0x084.
The Maximum payload size is 256 Bytes for the
Avalon-MM interface and for the Avalon-MM with
DMA interface.
Completion
timeout
range
ABCD
BCD
ABC
AB
B
A
None
ABCD
Indicates device function support for the optional
completion timeout programmability mechanism. This
mechanism allows system software to modify the
completion timeout value. This field is applicable only to
Root Ports and Endpoints that issue requests on their
own behalf. This parameter must be set to NONE for the
Avalon-MM with DMA interface. Completion timeouts
are specified and enabled in the Device Control 2
register (0x0A8) of the
PCI Express Capability Structure
Version
. For all other functions this field is reserved and
must be hardwired to 0x0000b. Four time value ranges
are defined:
• Range A: 50 us to 10 ms
• Range B: 10 ms to 250 ms
• Range C: 250 ms to 4 s
• Range D: 4 s to 64 s
Bits are set to show timeout value ranges supported. The
function must implement a timeout value in the range
50 s to 50 ms. The following values specify the range:
• None—Completion timeout programming is not
supported
• 0001 Range A
• 0010 Range B
• 0011 Ranges A and B
• 0110 Ranges B and C
• 0111 Ranges A, B, and C
• 1110 Ranges B, C and D
• 1111 Ranges A, B, C, and D
4-8
Device Capabilities
UG-01145_avmm_dma
2015.11.02
Altera Corporation
Parameter Settings
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