Arria® 10 and Cyclone® 10 GX Avalon® Memory-Mapped (Avalon-MM) Interface for PCI Express* User Guide

ID 683724
Date 9/10/2024
Public
Document Table of Contents

6.7.1.3. PCI Express Mailbox Registers

The PCI Express Root Complex typically requires write access to a set of PCI Express to Avalon-MM Mailbox registers and read-only access to a set of Avalon-MM to PCI Express mailbox registers. Eight mailbox registers are available.

The PCI Express to Avalon MM Mailbox registers are writable at the addresses shown in the following table. Writing to one of these registers causes the corresponding bit in the Avalon-MM Interrupt Status register to be set to a one.

Table 52.  PCI Express to Avalon-MM Mailbox Registers, 0x0800–0x081F

Address

Name

Access

Description

0x0800

P2A_MAILBOX0

RW

PCI Express-to-Avalon-MM Mailbox 0

0x0804

P2A_MAILBOX1

RW

PCI Express-to-Avalon-MM Mailbox 1

0x0808

P2A_MAILBOX2

RW

PCI Express-to-Avalon-MM Mailbox 2

0x080C

P2A_MAILBOX3

RW

PCI Express-to-Avalon-MM Mailbox 3

0x0810

P2A_MAILBOX4

RW

PCI Express-to-Avalon-MM Mailbox 4

0x0814

P2A_MAILBOX5

RW

PCI Express-to-Avalon-MM Mailbox 5

0x0818

P2A_MAILBOX6

RW

PCI Express-to-Avalon-MM Mailbox 6

0x081C

P2A_MAILBOX7

RW

PCI Express-to-Avalon-MM Mailbox 7

The Avalon-MM to PCI Express Mailbox registers are read at the addresses shown in the following table. The PCI Express Root Complex should use these addresses to read the mailbox information after being signaled by the corresponding bits in the Avalon-MM to PCI Express Interrupt Status register.

Table 53.  Avalon-MM to PCI Express Mailbox Registers, 0x0900–0x091F

Address

Name

Access

Description

0x0900

A2P_MAILBOX0

RO

Avalon-MM-to-PCI Express Mailbox 0

0x0904

A2P_MAILBOX1

RO

Avalon-MM-to-PCI Express Mailbox 1

0x0908

A2P_MAILBOX2

RO

Avalon-MM-to-PCI Express Mailbox 2

0x090C

A2P_MAILBOX3

RO

Avalon-MM-to-PCI Express Mailbox 3

0x0910

A2P_MAILBOX4

RO

Avalon-MM-to-PCI Express Mailbox 4

0x0914

A2P_MAILBOX5

RO

Avalon-MM-to-PCI Express Mailbox 5

0x0918

A2P_MAILBOX6

RO

Avalon-MM-to-PCI Express Mailbox 6

0x091C

A2P_MAILBOX7

RO

Avalon-MM-to-PCI Express Mailbox 7