Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 7/19/2024
Public
Document Table of Contents

13.4.4.6. Programming QoS Limiter Mode

QoS bandwidth limiter mode is mode 1. To put the QoS generator in limiter mode, set the registers as shown in the following table.

Table 392.  QoS Generator Register Values for Limiter Mode
Register Field Value
I_main_QosGenerator_Mode MODE 1
I_main_QosGenerator_Priority P0 Urgency for write transactions
I_main_QosGenerator_Priority P1 Urgency for read transactions
I_main_QosGenerator_Bandwidth BANDWIDTH

Maximum bandwidth.

Value = (bandwidth / frequency) * 256

I_main_QosGenerator_Saturation SATURATION Measurement window for bandwidth, in units of bytes/16. This register specifies the maximum number of bytes that the initiator can transmit or receive at full speed before the limiter triggers.

Higher priority (urgency) values mean that a packet receives preferential treatment at each arbitration node. For detailed information about setting bandwidth and saturation, refer to Bandwidth and Saturation. When you switch QoS modes, the bandwidth counter is reset.