Motorola MPC823e Reference Manual page 1075

Development Capabilities and Interface
Half-Word Working Mode Example 2
Data size: Half-word.
Address: Greater than or equal to 0x00000002 and less than 0x0000000e.
Data value: Greater than 0x4e204e20 and less than 0x9c409c40.
Programming option:
One L-address comparator = 0x00000001 and program for greater than.
One L-address comparator = 0x0000000e and program for less than.
One L-data comparator = 0x4e204e20 and program for greater than.
One L-data comparator = 0x9c409c40 and program for less than.
CGBMSK and CHBMSK fields of the LCTRL1 = 0xe.
Both L-data comparators program to half-word or word mode.
Result:
The event will be correctly detected if the compiler chooses a load/store instruction with
a data size of half-word. If the compiler chooses load/store instructions with a data size
greater than half-word (word, multiple), there might be some false detections.
This example uses Figure 20-2 to show the possible false detects that must be ignored by
the software that handles the breakpoints.
POSSIBLE FALSE DETECT ON THESE HALF-WORDS WHEN USING WORD/MULTIPLE
Figure 20-2. Example 2 False Detect on Watchpoint/Breakpoint
20.3.1.3 CONTEXT-DEPENDENT FILTER. The core can only be programmed to
recognize internal breakpoints when the MSR
breakpoints. When it is programmed only to recognize internal breakpoints or when
MSR = 1, all parts of the code can be debugged, except when the save and restore
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register 0 (SRR0), save and restore register 1 (SRR1), data address register (DAR), and
data storage interrupt status register (DSISR) are busy and MSR
20-14
0X00000000
0X00000004
0X00000008
0X0000000C
0X00000010
bit is set or to always recognize internal
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MPC823e REFERENCE MANUAL
= 0.
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