SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
The HBA DMA facilitates the reception of the D2H FISs into host system memory. The reception is enabled by the user setting SATA_PxCMD[4] FRE to 0b1. The software is allowed to change the SATA_PxFB / SATA_PxFBU contents and thus move the FIS reception area to different system memory locations, if SATA_PxCMD[14] FR is cleared, which occurs after software writes SATA_PxCMD[4] FRE = 0b0. In this case, further FIS reception is blocked when the internal RxFIFO becomes full. Before setting SATA_PxCMD[4] FRE to 0x1, the user software must ensure that a valid address is programmed into the SATA_PxFB / SATA_PxFBU registers.
The HBA port stores the unknown FISs (up to 64 bytes) in system memory but does not have a specified behavior to indicate an error condition on reception. The unknown FISs must be handled specifically by user software.