SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
The counters can be configured to alter their behavior based on the state of the CPU in the subsystem supported by the SCTM. The FREE bit in the SCTM_CTCR_WT_j or SCTM_CTCR_WOT_j register determines if the counter continues to operate when the processor enters the debug-halt state. When this bit is 0 (the default), the counter stops incrementing while the debug-halt input from the CPU is asserted. Normal operation resumes when the processor exits the debug halt state and the debug-halt input is deasserted. When the FREE bit is 1, the state of the debug-halt input is not used to control counter operation.
The IDLE bit in the SCTM_CTCR_WT_j or SCTM_CTCR_WOT_j register determines if the counter continues to operate when the processor enters the IDLE state (the processor is no longer executing instructions and is waiting for a wakeup event). When this bit is 0 (the default), the counter stops incrementing while the IDLE state input from the CPU is asserted. Normal operation resumes when the processor exits the idle state and the idle state INPUT is deasserted. When the IDLE bit is 1, the state of the idle input does not control counter operation.
Not all subsystems may contain a processor or the subsystem processor may not support debug halt and/or idle modes. In this case, the processor state inputs to the SCTM are tied to the inactive value.
When there are multiple CPUs in a subsystem, the processor state inputs can be sourced from a single processor, or they can be the logical OR of the processor state signals from all CPUs in the subsystem.