Nexus
MPC5566 Microcontroller Reference Manual, Rev. 2
25-52 Freescale Semiconductor
25.13.2.6 Program Correlation Messages
Program correlation messages are used to correlate events to the program flow that may not be associated
with the instruction stream. To maintain accurate instruction tracing information when entering debug
mode or a CPU low power mode (where tracing may be disabled), this message is sent upon entry into one
of these two modes and includes the instruction count and branch history. Program correlation is messaged
out in the following format:
Figure 25-34. Program Correlation Message Format
25.13.2.7 BTM Overflow Error Messages
An error message occurs when a new message cannot be queued because the message queue is full. The
FIFO discards incoming messages until the queue is completely empty. After it is empty, an error message
is queued. The error encoding indicates which message types were denied queueing while the FIFO was
emptying.
If only a program trace message attempts to enter the queue while it is being emptied, the error message
incorporates the program trace only error encoding (00001). If both OTM and program trace messages
attempt to enter the queue, the error message incorporates the OTM and program trace error encoding
(00111). If a watchpoint also attempts to be queued while the FIFO is being emptied, then the error
message incorporates error encoding (01000).
NOTE
The OVC bits within the DC1 register can be set to delay the CPU to
alleviate (but not eliminate) potential overrun situations.
Error information is messaged out in the following format:
Figure 25-35. Error Message Format
HIST
MSB LSB
234
I-CNT EVCODE SRC
5
4 bits
1
TCODE (100001)
4 bits1–8 bits1–32 bits 6 bits
Max length = 54 bits; Min length = 16 bits
ECODE (00001 / 00111 / 01000)
MSB LSB
12
SRC TCODE (001000)
3
6 bits4 bits5 bits
Fixed length = 15 bits
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