MPC555
/
MPC556
DEVELOPMENT SUPPORT
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
21-14
21.3.1.3 Examples
• A fully supported scenario:
Looking for:
Data size: Byte
Address: 0x00000003
Data value: greater than 0x07 and less than 0x0c
Programming options:
One L-address comparator = 0x00000003 and program for equal
One L-data comparator = 0x00000007 and program for greater than
One L-data comparator = 0x0000000c and program for less than
Both byte masks = 0xe
Both L-data comparators program to byte mode
Result: The event will be correctly detected regardless of the load/store instruc-
tion the compiler chooses for this access
• A fully supported scenario:
Looking for:
Data size: half-word
Address: greater than 0x00000000 and less than 0x0000000c
Data value: greater than 0x4e204e20 and less than 0x9c409c40
Programming option:
One L-address comparator = 0x00000000 and program for greater than
One L-address comparator = 0x0000000c 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
Both byte masks = 0x0
Both L-data comparators program to half-word mode
Result: The event will be correctly detected as long as the compiler does not use
a load/store instruction with data size of byte.
• A
partially
supported scenario:
Looking for:
Data size: half-word
Address: greater than or equal 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
Both byte masks = 0x0
Both L-data comparators program to half-word mode or to word mode
Result: The event will be correctly detected if the compiler chooses a load/store
instruction with data size of half-word. If the compiler chooses load/store instruc-
tions with data size greater than half-word (word, multiple), there might be some
false detections.
These can be ignored only by the software that handles the breakpoints. The following
figure illustrates this
partially
supported scenario.
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