GTS AXI Streaming Intel® FPGA IP for PCI Express* User Guide

ID 813754
Date 8/07/2024
Public
Document Table of Contents

8.6.6.2. ATS Capability Register and Control Register

Address: Offset 0x4

The lower 16 bits of this location is defined as the ATS Capability Register and the upper 16 bits as the ATS Control Register.

Table 85.  ATS Capability Register and Control Register Description
Bit Location Description Attributes Default
4:0

Invalidate Queue Depth.

The number of Invalidate Requests that the Function can accept before putting backpressure on the upstream connection. If 0, the Function can accept 32 Invalidate Requests.

This field is hardwired to 0 for VFs. VFs use the setting from the parent PF’s ATS Capability Register.

RO 0
5

Page Aligned Request.

If Set, indicates the Untranslated Address is always aligned to a 4096 byte boundary. This bit is hardwired to 1.

RO

Programmed via Programming Interface

6 Global Invalidate Supported. RO

Programmed via Programming Interface

15:7 Reserved RO 0
20:16

Smallest Translation Unit (STU)

This value indicates to the Function the minimum number of 4096-byte blocks that is indicated in a Translation Completions or Invalidate Requests. This is a power of 2 multiplier and the number of blocks is 2STU. A value of 0 indicates one block and a value of 0x1F indicates 231 blocks (or 8 TB total).

This field is hardwired to 0 for VFs. VFs use the setting from the parent PF's ATS Control Register.

RO 0
30:21 Reserved RO 0
31

Enable (E).

When Set, the Function is enabled to cache translations.

You must obtain this information from the configuration intercept interface.

RW 0