3.6 QoS, region, and NSAID signaling

The AXI protocol supports QoS, region, and NSAID signaling. Although the AHB protocol does not support these signals, the AHB5 to AXI5 bridge has QoS, region, and NSAID signals on the AHB slave interface.

QoS signaling

To support Quality of Service (QoS) signaling, the bridge provides the hqos[3:0] signal, which is not included in the AHB5 protocol.

The hqos[3:0] sideband signal is active during the address phase and the bridge routes its value to the appropriate read or write address channel, on arqos[3:0] and awqos[3:0], respectively.

The bridge does not support QoS Accept signaling, which was introduced in the AXI5 protocol.

Region identifier signaling

To support region identifier signaling, the bridge provides the hregion[3:0] signal, which is not included in the AHB5 protocol.

The hregion[3:0] sideband signal is active during the address phase and the bridge routes its value to the appropriate read or write address channel, on arregion[3:0] and awregion[3:0], respectively.

NSAID signaling

To support Non-secure Access Identifier (NSAID) signaling, the bridge provides the hnsaid[3:0] signal, which is not included in the AHB5 protocol.

The hnsaid[3:0] sideband signal is active during the address phase and the bridge routes its value to the appropriate read or write address channel, on arnsaid[3:0] and awnsaid[3:0], respectively.

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