PXR40RM Datasheet, PDF (1366/1434 Pages) Freescale Semiconductor, Inc – PXR40 Microcontroller

Nexus Development Interface (NDI)
31.14.6.2 DTM Message Formats
The Nexus3 module supports five types of DTM messages: data write, data read, data write
synchronization, data read synchronization and error messages.
31.14.6.2.1 Data Write Messages
The data write message contains the data write value and the address of the write access, relative to the
previous data trace message. Data write message information is messaged out in the following format:
5
4
3
2
1
DATA
U-ADDR
DSZ
SRC
msb 1–64 bits
1–32 bits
3 bits
4 bits
Max length = 109 bits; Min length = 15 bits
Figure 31-30. Data Write Message Format
TCODE (000101)
6 bits lsb
31.14.6.2.2 Data Read Messages
The data read message contains the data read value and the address of the read access, relative to the
previous data trace message. Data read message information is messaged out in the following format:
5
4
3
2
1
DATA
U-ADDR
DSZ
SRC
msb 1–64 bits
1–32 bits
3 bits
4 bits
Max length = 109 bits; Min length = 15 bits
Figure 31-31. Data Read Message Format
TCODE (000110)
6 bits lsb
NOTE
For the e200z7 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.
31.14.6.2.3 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).
31-50
PXR40 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor