SPRZ429N July 2014 – July 2024 AM5726 , AM5728 , AM5729
SATA 6-Gbps to 3-Gbps Negotiation Can Fail
Medium
The device is specified to support only 3-Gbps speed. Per the standard, when used with 6-Gbps capable devices, a speed negotiation sequence must take place. During speed negotiation sequence with a 6-Gbps device, the SATA controller may potentially misinterpret a valid 3-Gbps stream and attempt to establish link even though the external SATA device is sending at 6-Gbps speed. If this occurs, the link controller will be at an invalid state requiring a reset to recover.
There is no direct workaround to reliably prevent the invalid state during gen3 negotiation. For development, the user may retry multiple times to attempt to establish the link. However, a robust connection requires avoiding the 6-Gbps negotiation completely. This can be done by:
SR 1.0
TDA2x: 1.0
DRA75x, DRA74x: 1.0
AM572x: 1.0