Motorola MPC533 Reference Manual page 1010

Watchpoint Support
watchpoints occur, a message is sent to the signal output formatter to be messaged out (the
general message queue is bypassed to prevent watchpoint messages from being cancelled
in the event of a queue overflow). The watchpoint message has the second highest priority.
Refer to Section 22.2.2.1, "Message Priority," for further details on message priorities. The
watchpoint message contains the watchpoint code which indicates all the unique
watchpoints have occurred since the last watchpoint message. If duplicate watchpoints
occur before the watchpoint message is sent out, a watchpoint overrun message is
generated. The watchpoint source field will indicate which watchpoints occurred.
The watchpoint message has the following format:
22.7.1.1 Watchpoint Source Field
The watchpoint source field is outlined in Table 22-32.
22.7.2 Watchpoint Overrun Error Message
A watchpoint overrun error occurs when the same watchpoint occurs multiple times before
the first occurrence of that watchpoint has been messaged out. The watchpoint message
(which has information of all the watchpoints that occurred prior to the detection of the
same watchpoint occurring multiple times) will be sent before the error message can be
sent.
The overrun error causes further watchpoint occurrences to be ignored, until the error
message has been sent. The error code within the error message indicates that a watchpoint
overrun error has occurred. Refer to Table 22-20.
The error message has the following format:
22-78
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
[6 bits]
TCODE (15)
Length = 12 bits
Figure 22-69. Watchpoint Message Format
Table 22-32. Watchpoint Source
Watchpoint Source
0bXXXXX1
0bXXXX1X
0bXXX1XX
0bXX1XXX
0bX1XXXX
0b1XXXXX
MPC533 Reference Manual
[6 bits]
Watchpoint Source
Description
First L-bus watchpoint (LW0)
Second L-bus watchpoint (LW1)
First I-bus watchpoint (IW0)
Second I-bus watchpoint (IW1)
Third I-bus watchpoint (IW2)
Fourth I-bus watchpoint (IW3)
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