Threshold Registers

Zynq UltraScale+ Device Technical Reference Manual (UG1085)

Document ID
UG1085
Release Date
2022-09-15
Revision
2.3 English

Bit Field Name

Description

RD_LPR_THRSLD

Read LPR threshold.

RD_HPR_THRSLD

Read HPR threshold.

WR_THRSLD

Write threshold.

When the DDRC CAM levels reaches their threshold, the QoS controller applies the following throttling rules.

Rule

Description

Read channel throttle rules

If ((slots available in read LPR CAM £ read LPR threshold) && PORTn_LPR_CTRL == 1),
then assert pa_rmark to DDRC for all best effort ports.

If ((slots available in read HPR CAM £ read HPR threshold) && PORTn_HPR_CTRL == 1),
then assert pa_rmark to DDRC for all low-latency ports

Write channel throttle rule

If ((slots available in write CAM £ write CAM threshold) && PORTn_WR_CTRL == 1),
then assert pa_wmask to DDRC for all best-effort ports.