MCF51QE128 MCU Series Reference Manual, Rev. 3
48 Freescale Semiconductor
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Chapter 3 Modes of Operation
Individual power states are discussed in more detail in the following sections.
3.4 Debug Mode
Debug mode functions are managed through the background debug controller (BDC) in the Version 1
ColdFire core. The BDC provides the means for analyzing MCU operation during software development.
The debug interface is used to program a bootloader or user application program into the flash program
memory before the MCU is operated in run mode for the first time. When the MCF51QE128/64/32 is
shipped from the Freescale Semiconductor factory, the flash program memory is erased by default unless
specifically noted, so there is no program that could be executed in run mode until the flash memory is
initially programmed. The debug interface can also be used to erase and reprogram the flash memory after
it has been previously programmed.
See Chapter 18, “Version 1 ColdFire Debug (CF1_DEBUG),” for more details regarding the debug
interface.
3.5 Secure Mode
While the MCU is in secure mode, there are severe restrictions on which debug commands can be used.
In this mode, only the upper byte of the core’s XCSR, CSR2, and CSR3 registers can be accessed. See
Chapter 18, “Version 1 ColdFire Debug (CF1_DEBUG),” for details.
8
Stop3 Run Interrupt when LPWUI=1
Run Stop3 Pre-configure settings shown in Tab l e 3 - 1 , execute
STOP instruction
9
Stop4 Halt
When a BACKGROUND command is received
through the BKGD/MS pin (ENBDM must equal
one).
Halt Stop4 Not supported.
10
Halt Run GO instruction issued via BDM
Run Halt
When a BACKGROUND command is received
through the BKGD/MS pin OR
When a HALT instruction is executed OR
When encountering a BDM breakpoint
11
Wait Halt
When a BACKGROUND command is received
through the BKGD/MS pin (ENBDM must equal
one).
Halt Wait Not supported.
1An analog connection from this pin to the on-chip regulator wakes up the regulator, which then initiates a
power-on-reset sequence.
Table 3-2. Triggers for Transitions Shown in Figure 3-2 (continued)
Transition # From To Trigger