Control register access (cra) avalon-mm slave port – Altera Arria 10 Avalon-MM User Manual

Page 88

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Address

Name

Access

Mode

Description

0x3B14

P2A_MAILBOX5

RO

PCI Express-to-Avalon-MM mailbox 5

0x3B18

P2A_MAILBOX6

RO

PCI Express-to-Avalon-MM mailbox 6

0x3B1C

P2A_MAILBOX7

RO

PCI Express-to-Avalon-MM mailbox 7

Control Register Access (CRA) Avalon-MM Slave Port

Table 6-23: Configuration Space Register Descriptions

For registers that are less than 32 bits, the upper bits are unused.

Byte Offset

Register

Dir

Description

14'h3C00

cfg_dev_ctrl[15:0]

O

cfg_devctrl[15:0]

is device control for the PCI

Express capability structure.

14'h3C04

cfg_dev_ctrl2[15:0]

O

cfg_dev2ctrl[15:0]

is device control 2 for the

PCI Express capability structure.

14'h3C08

cfg_link_ctrl[15:0]

O

cfg_link_ctrl[15:0]

is the primary Link Control

of the PCI Express capability structure.
For Gen2 or Gen3 operation, you must write a 1’b1

to Retrain Link bit (Bit[5] of the

cfg_link_ctrl)

of

the Root Port to initiate retraining to a higher data

rate after the initial link training to Gen1 L0 state.

Retraining directs the LTSSM to the Recovery state.

Retraining to a higher data rate is not automatic for

the Arria 10 Hard IP for PCI Express IP Core even

if both devices on the link are capable of a higher

data rate.

14'h3C0C

cfg_link_ctrl2[15:0]

O

cfg_link_ctrl2[31:16]

is the secondary Link

Control register of the PCI Express capability

structure for Gen2 operation.
When

tl_cfg_addr=2

,

tl_cfg_ctl

returns the

primary and secondary Link Control registers,

{cfg_link_ctrl[15:0], cfg_link_

ctrl2[15:0]}

, the primary Link Status register

contents is available on

tl_cfg_sts[46:31]

.

For Gen1 variants, the link bandwidth notification

bit is always set to 0. For Gen2 variants, this bit is

set to 1.

6-22

Control Register Access (CRA) Avalon-MM Slave Port

UG-01145_avmm

2015.05.14

Altera Corporation

Registers

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