Development Capabilities and Interface
20-18 MPC823e REFERENCE MANUAL MOTOROLA
DEVELOPMENT
20
CAPABILITIES & INTERFACE
The four load/store data events, combined with the match events of the load/store address
comparators and the instruction watchpoints, are used to generate the load/store
watchpoints and breakpoint according to your programming.
When programming the load/store watchpoints to ignore L-address and L-data events, the
instruction must be a load/store instruction to trigger the load/store watchpoint event.
20.3.2.3 COUNTER SUPPORT. There are two 16-bit down counters that count one of the
instruction watchpoints or one of the load/store watchpoints. Both generate the
corresponding breakpoint when they reach zero. When working in masked mode, the
counters do not count detected watchpoints when MSR
RI
=0. Counter values are not
predictable if they are counting watchpoints programmed on the instructions that alter the
counters. Readings from the active counters must be synchronized by inserting a sync
instruction before a read is performed. For details, refer to Section 20.3.1.2 Byte And Half-
Word Working Modes.
Table 20-5. Load/Store Data Events
EVENT NAME EVENT FUNCTION
G (Gmatch0 | Gmatch1 | Gmatch2 | Gmatch3)
H (Hmatch0 | Hmatch1 | Hmatch2 | Hmatch3)
(G & H) ((Gmatch0 & Hmatch0) | (Gmatch1 & Hmatch1) | (Gmatch2 & Hmatch2) | (Gmatch3 & Hmatch3))
(G | H) ((Gmatch0 | Hmatch0) | (Gmatch1 | Hmatch1) | (Gmatch2 | Hmatch2) | (Gmatch3 | Hmatch3))
NOTE:
& denotes a logical AND, but | denotes a logical OR.
Table 20-6. Load/Store Watchpoints Programming Options
NAME DESCRIPTION I-ADDRESS EVENT
PROGRAMMING
OPTIONS
L-ADDRESS EVENT
PROGRAMMING
OPTIONS
L-DATA EVENT
PROGRAMMING
OPTIONS
LW0 First Load/Store
Watchpoint
IW0, IW1, IW2, IW3,
Ignore I-address events
Comparator E
Comparator F
Comparators (E & F)
Comparators (E | F)
Ignore L-address events
Comparator G
Comparator H
Comparators (G & H)
Comparators (G | H)
Ignore L-data Events
LW1 Second Load/
Store
Watchpoint
IW0, IW1, IW2, IW3,
Ignore I-address events
Comparator E
Comparator F
Comparators (E & F)
Comparators (E | F)
Ignore L-address events
Comparator G
Comparator H
Comparators (G & H)
Comparators (G | H)
Ignore L-data Events
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