SPRUJ28E November 2021 – September 2024 AM68 , AM68A , TDA4AL-Q1 , TDA4VE-Q1 , TDA4VL-Q1
DSS supports the following security features:
Secure Mode
The DISPC supports secure mode configuration registers (DSS0_VID_SECURE, DSS0_WB_SECURE, DSS0_OVR_SECURE and DSS0_VP_SECURE) which defines the "secure mode" attribute of each pipeline, overlay manager, and video port instance in DISPC. These registers 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 ports are in a "non-secure mode". The corresponding SECURE bits in the DSS0_VID_SECURE, DSS0_WB_SECURE, DSS0_OVR_SECURE and DSS0_VP_SECURE registers 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 SECURE register bits are non-active and DISPC will behave as non-secure module.
Illegal Connection Prevention
The DISPC hardware enforces the following rules to prevent an illegal connection: