ColdFire Debug History
MCF548x Reference Manual, Rev. 3
Freescale Semiconductor 8-61
The move-to-SR and RTE instructions include an optional PSTDDATA = 0x3 value, indicating an entry
into user mode. Additionally, if the execution of a RTE instruction returns the processor to emulator mode,
a multiple-cycle status of 0xD is signaled.
Similar to the exception processing mode, the stopped state (PSTDDATA = 0xE) and the halted state
(PSTDDATA = 0xF) display this status throughout the entire time the ColdFire processor is in the given
mode.

8.8 ColdFire Debug History

This section describes the origins of the ColdFire debug systems.

8.8.1 ColdFire Debug Classic: The Original Definition

The original design, Revision A, provided debug support in three separate areas:
Real-time trace
Background debug mode (BDM)
Real-time debug
The real-time debug features may be accessed from the external BDM emulator or from the supervisor
programming model of the processor. The hardware breakpoint registers include: a PC breakpoint + mask,
two address registers for defining a specific address or a range of addresses, and a data breakpoint + mask.
The original design supported breakpoints of the form:
if PC_breakpoint is triggered
then respond using user-defined configuration
if Address_breakpoint {&& Data_breakpoint} is triggered
then respond using user-defined configuration
Two-level triggers of the form:
if PC_breakpoint is triggered
then if Address_breakpoint {&& Data_breakpoint} is triggered
then respond using user-defined configuration
if Address_breakpoint {&& Data_breakpoint} is triggered
then if PC_breakpoint is triggered
then respond using user-defined configuration
movec.l Ry,Rc PSTDDATA = 0x1, {8, ASID}
rte PSTDDATA = 0x7, {0xB, source operand}, {3}, {0xB, source operand}, {DD},
PSTDDATA = 0x5, {[0x9AB], target address}
stop #<data> PSTDDATA = 0x1,
PSTDDATA = 0xE
wdebug.l <ea>y PSTDDATA = 0x1, {0xB, source, 0xB, source}
Table 8-34. PSTDDATA Specification for Supervisor-Mode Instructions (Continued)
Instruction Operand Syntax PSTDDATA