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| Home > Program Trace Macrocell Programmers Model > About the access permissions for PTM registers | |||
A PTM implements controls on accesses to the PTM registers. These controls depend on the register access model implemented by the PTM. The usual access models are summarized in PTM register access models.
A PTM might be part of a system that is implemented with multiple power domains. A typical implementation might implement two domains that can be independently powered down, for example:
the core power domain powers the processor that is being traced, and contains most of the PTM logic, including the trace registers
a debug power domain contains the trace output logic, including the programming interface or interfaces.
However, the system that includes the PTM might be implemented in a single power domain. An implementation of this type is called a SinglePower system.
The access controls on memory-mapped accesses to PTM registers depend on whether the system is implemented with multiple power domains, or as a SinglePower system.
If your PTM is accessed using an ARM Debug Interface v5, see the access permissions descriptions in the ARM Debug Interface v5 Architecture Specification.
The types of access that can be made to the PTM registers are described in Access types. The access permissions that control PTM register accesses, and restrictions on PTM register accesses, are described in: