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9.3.2 MDM-AP Status Register
Table 9-4. MDM-AP Status register assignments
Bit
Name
Description
0
Flash Mass Erase Acknowledge
The Flash Mass Erase Acknowledge bit is cleared after any system reset.
The bit is also cleared at launch of a mass erase command due to write of
Flash Mass Erase in Progress bit in MDM AP Control Register. The Flash
Mass Erase Acknowledge is set after Flash control logic has started the
mass erase operation.
When mass erase is disabled (via MEEN and SEC settings), an erase
request due to setting of Flash Mass Erase in Progress bit is not
acknowledged.
1
Flash Ready
Indicates Flash has been initialized and debugger can be configured even
if system is continuing to be held in reset via the debugger.
2
System Security
Indicates the security state. When secure, the debugger does not have
access to the system bus or any memory mapped peripherals. This bit
indicates when the part is locked and no system bus access is possible.
3
System Reset
Indicates the system reset state.
0 System is in reset.
1 System is not in reset.
4
Reserved
5
Mass Erase Enable
Indicates if the MCU can be mass erased or not
0 Mass erase is disabled.
1 Mass erase is enabled .
6
Backdoor Access Key Enable
Indicates if the MCU has the backdoor access key enabled.
0 Disabled
1 Enabled
7
LP Enabled
Decode of SMC_PMCTRL[STOPM] field to indicate that VLPS, LLS, or
VLLSx are the selected power mode the next time the ARM Core enters
Deep Sleep.
0 Low Power Stop Mode is not enabled.
1 Low Power Stop Mode is enabled.
Usage intended for debug operation in which Run to VLPS is attempted.
Per debug definition, the system actually enters the Stop state. A
debugger should interpret deep sleep indication (with SLEEPDEEP and
SLEEPING asserted), in conjunction with this bit asserted as the
debugger-VLPS status indication.
8
Very Low Power Mode
Indicates current power mode is VLPx. This bit is not ‘sticky’ and should
always represent whether VLPx is enabled or not.
This bit is used to throttle SWD_CLK frequency up/down.
9
LLS Mode Exit
This bit indicates an exit from LLS mode has occurred. The debugger will
lose communication while the system is in LLS (including access to this
register). Once communication is reestablished, this bit indicates that the
system had been in LLS. Since the debug modules held their state during
LLS, they do not need to be reconfigured.
Table continues on the next page...
Chapter 9 Debug
KL27 Sub-Family Reference Manual , Rev. 5, 01/2016
Freescale Semiconductor, Inc.
107