3.5 Exclusive and locked accesses

The AHB5 to AXI5 bridge can translate AHB5 Exclusive accesses to AXI5 Exclusive accesses. The bridge sets AXI ID to the value of the hmaster signal.

For Exclusive accesses, the bridge sets AxCACHE[3:2] LOW because the AXI protocol does not permit an Exclusive access to Cacheable memory.

Locked accesses

The bridge does not support locked AHB transfers because the AXI4 and AXI5 protocols do not support locked transactions.

The AHB_LOCK_RESP configuration parameter controls how the bridge behaves when it receives a locked AHB transfer. If the bridge receives a locked AHB transfer (hmastlock is HIGH), then it either:

  • Ignores the lock and forwards the transfer as if hmastlock is LOW.
  • Blocks the transfer and responds with an ERROR response.
Non-Confidential - BetaPDF file icon PDF version101375_0000_00_en
Copyright © 2018 Arm Limited or its affiliates. All rights reserved.