Nexus
MPC5566 Microcontroller Reference Manual, Rev. 2
Freescale Semiconductor 25-59
NOTE
For the e200z6 based CPU, the doubleword encoding (data size = 0b000)
indicates a doubleword access and sends out as a single data trace message
with a single 64-bit data value.
25.14.6.2.3 DTM Overflow Error Messages
An error message occurs when the next message is denied service because the message queue is full. The
FIFO discards all incoming messages until the queue is completely empty. After it is empty, an error
message is queued that indicates the message types denied into the queue while the FIFO is emptying.
If a data trace message only attempts to enter the queue while it is emptying, the error message incorporates
the data trace only error encoding (00010). If both OTM and data trace messages attempt to enter the
queue, the error message incorporates the OTM and data 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 25-45. Error Message Format
25.14.6.2.4 Data Trace Synchronization Messages
A data trace write/read with sync. message is messaged via the auxiliary port (provided data trace is
enabled) for the following conditions (refer to Table 25-37):
• Initial data trace message after exit from system reset or whenever data trace is enabled
• Upon exiting debug mode
• After occurrence of queue overrun (can be caused by any trace message), provided data trace is
enabled
• After the periodic data trace counter has expired indicating 255 without-sync data trace messages
have occurred since the last with-sync message occurred
• Upon assertion of the event in (EVTI) pin, the first data trace message is a synchronization message
if the EIC bits of the DC1 register have enabled this feature
• Upon data trace write/read after the previous DTM message was lost due to an attempted access to
a secure memory location
DATA
MSB LSB
234
U-ADDR DSZ SRC
5
4 bits
1
TCODE (000110)
3 bits1–32 bits1–64 bits 6 bits
Max length = 109 bits; Min length = 15 bits
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