Power Requests During Debug
445
SLAU356I – March 2015 – Revised June 2019
Copyright © 2015–2019, Texas Instruments Incorporated
Power Control Manager (PCM)
8.24.1 Debug During Active Modes
The debugger can connect and halt the device any time after the boot, except the following conditions of
device security:
•
JTAG and SWD locked.
•
IP protection active, with CPU executing in one of the secure memory zones.
Assuming that the device is in a nonsecure mode, the user can plug in the debugger cable and issue a
halt, thereby halting the CPU. Debugger can then run or step through the code or access the memory
map.
When the user requests a connect:
•
The debugger activates DBGPWRUPREQ and SYSPWRUPREQ through SWJ-DP. These are VCC
domain signals.
If the user does a disconnect through the debugger command (controlled disconnect), the debugger
issues a 'run free' command. At this point, the debugger cable can be removed safely. If the CPU now
runs to WFI or WFE, it stays in SLEEP, because CPU is kept running and the debugger is disconnected. If
the user disconnects the cable at any time (not recommended), the processor stays in whatever state it
was before the cable was disconnected.
8.24.2 Debug During LPM0 Modes
The behavior is identical to debug when CPU is active. If the device is in LPM0 mode, and the debugger
connects to the processor, the CPU is halted and the device enters the active mode the LPM0 was
entered from. This discontinues the sleep mode of the CPU. The PC points to either the WFI or WFE
instruction or, for the case of sleep-on-exit, at the first instruction after the return of the last pending
interrupt. Stepping or running through simply re-execute the same instruction. A step is followed by a
HALT, which also discontinues the SLEEP mode of the CPU.
If the user does a disconnect through the debugger command (controlled disconnect), the debugger
issues a 'run free' command. At this point, the debugger cable can be removed safely. If CPU now runs
into WFI or WFE, it stays in SLEEP because CPU is kept running, and the debugger is disconnected. If
the user removes the cable at any time (not recommended), the processor is left in whatever state it was
before the cable was disconnected.
8.24.3 Debug During LPM3, LPM4, and LPMx.5 Modes
Debug under LPM3, LPM4, and LPMx.5 modes behaves differently from the nondebug mode. If an active
debug session is ongoing, the device does not enter LPM3, LPM4, or LPMx.5 mode but remains in LPM0
mode corresponding to the active mode. If, the device is already in the LPM3, LPM4, or LPMx.5 mode of
operation and debug is initiated, then PCM initiates a wake up to the system to give control back to the
debugger.
8.25 Wake-up Sources From Low-Power Modes
and
list the available wake-up sources from low-power modes.
Table 8-10. Wake-up Sources from Low-Power Modes for MSP432P401R and MSP432P401M
Devices
Peripheral
Wake-up Source
LPM0
LPM3
LPM4
LPM3.5
LPM4.5
eUSCI_A
Any enabled interrupt
Yes
–
–
–
–
eUSCI_B
Any enabled interrupt
Yes
–
–
–
–
Timer_A
Any enabled interrupt
Yes
–
–
–
–
Timer32
Any enabled interrupt
Yes
–
–
–
–
Comparator_E
Any enabled interrupt
Yes
–
–
–
–
ADC14
Any enabled interrupt
Yes
–
–
–
–
AES256
Any enabled interrupt
Yes
–
–
–
–
DMA
Any enabled interrupt
Yes
–
–
–
–