Nexus
MPC5566 Microcontroller Reference Manual, Rev. 2
25-58 Freescale Semiconductor
25.14.6.1 Data Trace Messaging (DTM)
Data trace messaging for e200z6 is accomplished by snooping the e200z6 virtual data bus (between the
CPU and MMU), and storing the information for qualifying accesses (based on enabled features and
matching target addresses). The NZ6C3 module traces all data access that meet the selected range and
attributes.
NOTE
Data trace is only performed on the e200z6 virtual data bus. This allows for
data visibility for the incorporated data cache. Only e200z6 CPU initiated
accesses are traced. No DMA accesses to the NXDM system bus are traced.
Data trace messaging can be enabled in one of two ways:
• Setting the TM field of the DC1 register to enable data trace (DC1[TM]).
• Using WT[DTS] to enable data trace on watchpoint hits (e200z6 watchpoints are configured within
the Nexus1 module)
25.14.6.2 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.
25.14.6.2.1 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:
Figure 25-43. Data Write Message Format
25.14.6.2.2 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:
Figure 25-44. Data Read Message Format
DATA
MSB LSB
234
U-ADDR DSZ SRC
5
4 bits
1
TCODE (000101)
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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