Table 9-4. MDM-AP Status register assignments (continued)
Bit
Name
Description
This bit is set during the VLLSx recovery sequence. The VLLSx Mode Exit
bit is held until the debugger has had a chance to recognize that a VLLS
mode was exited and is cleared by a write of 1 to the VLLSx Status
Acknowledge bit in MDM AP Control register.
11 – 15
Reserved for future use
Always read 0.
16
Core Halted
Indicates the core has entered Debug Halt mode
17
Core SLEEPDEEP
Indicates the core has entered a low-power mode
SLEEPING==1 and SLEEPDEEP==0 indicates wait or VLPW mode.
SLEEPING==1 and SLEEPDEEP==1 indicates stop or VLPS mode.
18
Core SLEEPING
19 – 31
Reserved for future use
Always read 0.
9.4 Debug resets
The debug system receives the following sources of reset:
• Debug reset (the CDBGRSTREQ field within the DP CTRL/STAT register) that
allows the debugger to reset the debug logic.
• System POR reset
Conversely, the debug system is capable of generating system reset using the following
mechanism:
• A system reset in the DAP control register which allows the debugger to hold the
system in reset.
• SYSRESETREQ field in the NVIC Application Interrupt and Reset control register
• A system reset in the DAP control register which allows the debugger to hold the
core in reset.
9.5 Micro Trace Buffer (MTB)
The Micro Trace Buffer (MTB) provides a simple execution trace capability for the
Cortex-M0+ processor. When enabled, the MTB records changes in program flow
reported by the Cortex-M0+ processor, via the execution trace interface, into a
configurable region of the SRAM. Subsequently, an off-chip debugger may extract the
trace information, which would allow reconstruction of an instruction flow trace. The
MTB does not include any form of load/store data trace capability or tracing of any other
information.
Debug resets
KL02 Sub-Family Reference Manual, Rev. 2.1, July 2013
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Freescale Semiconductor, Inc.