The debug access port (DAP) provides off-chip debug tools with the capability to access the debug infrastructure and the PS, including all debug components and all memory-mapped locations of the PS. For security, authentication requirements must be met to be granted access rights. See Debug Authentication.
The DAP is divided into the following sub-components.
JTAG-DP |
Processes JTAG requests, decodes to select an access port (***-AP), requests for power on, and requests for debug reset. |
AXI-AP |
Provides an AXI master port for access to system memory-mapped locations (subject to authentication). |
APB-AP |
Provides an APB master port for access to the debug APB. |
JTAG-AP |
Provides eight JTAG master ports to control on-chip TAP controllers. |
APBMUX |
Provides access to the debug APB from the system (internal). |
DBGROM |
Provides pointers to other CoreSight components on the debug APB. |