SPRUIV7B May 2022 – September 2023 AM620-Q1 , AM623 , AM625 , AM625-Q1 , AM625SIP
DSS supports the following security features:
Secure Mode
DISPC supports a secure mode configuration register (DSS0_COMMON1_DISPC_SECURE) which defines the "secure mode: attribute of each pipeline, overlay manager, and video port instance in DISPC. This register can only be modified by a host with an appropriate secure privilege (MReqSecure=1). When the secure bit corresponding to an instance is set by a secure host, the instance is deemed to be in "secure mode" and the DISPC hardware prevents the output of the instance getting connected to a non-secure downstream module. Also, any DMA transfer initiated by a secure pipeline will have its OCP in-band signal MReqSecure set to HIGH to indicate that is a secure mode transaction request.
By default, all pipelines, overlay managers, and video port instances are in a "non-secure mode". The DSS0_COMMON1_DISPC_SECURE register bits are active, only when the DSS0_COMMON_DISPC_SECURE_DISABLE[0] SECURE_DISABLE register bit is configured properly to 0x0. When the SECURE_DISABLE bit is set to 0x1, the DSS0_COMMON1_DISPC_SECURE register bits are non-active and DISPC will behave as non-secure module.
Illegal Connection Prevention
DISPC hardware enforces the following rules to prevent an illegal connection: