MPC5553/MPC5554 Microcontroller Reference Manual, Rev. 5
Freescale Semiconductor 25-55
Figure 25-42. Data Read Message Format
NOTE
For the e200z6 based CPU, the doubleword encoding (data size = 0b000)
will indicate a doubleword access and will be sent out as a single data trace
message with a single 64-bit data value.
25.11.13.2.3 DTM Overflow Error Messages
An error message occurs when a new message cannot be queued due to the message queue being full. The
FIFO will discard incoming messages until it has completely emptied the queue. After it is emptied, an
error message will be queued. The error encoding will indicate which types of messages attempted to be
queued while the FIFO was being emptied.
If only a data trace message attempts to enter the queue while it is being emptied, the error message will
incorporate the data trace only error encoding (00010). If both OTM and data trace messages attempt to
enter the queue, the error message will incorporate 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 will
incorporate error encoding (01000).
NOTE
The OVC bits within the DC1 register can be set to delay the CPU in order
to alleviate (but not eliminate) potential overrun situations.
Error information is messaged out in the following format:
Figure 25-43. Error Message Format
25.11.13.2.4 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 (see Table 25-36):
• 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
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
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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