PXR40RM Datasheet, PDF (1355/1434 Pages) Freescale Semiconductor, Inc – PXR40 Microcontroller

Ownership trace information is messaged out in the following format:
3
2
Nexus Development Interface (NDI)
1
PROCESS
msb
32 bits
Fixed length = 42 bits
SRC
4 bits
TCODE (000010)
6 bits
lsb
Figure 31-14. Ownership Trace Message Format
31.12.2 OTM Error Messages
An error message occurs when a new message cannot be queued due to the message queue being full. The
FIFO discards incoming messages until the queue the queue is completely empty. After it empties, an error
message is queued. The error encoding indicate the message types denied service to the queue while the
FIFO was emptying.
If an OTM message only attempts to enter the queue while the queue is emptying, the error message
incorporates the OTM error encoding (00000) only. If OTM and either BTM or DTM messages attempt to
enter the queue, the error message incorporates the OTM and (program or data) trace error encoding
(00111). If a watchpoint also attempts to enter the queue while the FIFO is emptying, 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 (see Table 31-19):
3
2
1
ECODE (00000 / 00111 / 01000)
SRC
TCODE (001000)
msb
5 bits
4 bits
6 bits lsb
Fixed length = 15 bits
Figure 31-15. Error Message Format
31.12.3 OTM Flow
Ownership trace messages are generated when the operating system writes to the e200z7 process ID
register or the memory mapped ownership trace register.
The following flow describes the OTM process:
1. The process ID register is a system control register. It is internal to the e200z7 processor and can
be accessed by using PPC instructions mtspr and mfspr. The contents of this register are replicated
on the pins of the processor and connected to Nexus.
2. OTR/process ID register reads do not cause ownership trace messages to be transmitted by the
NZ7C3 module.
Freescale Semiconductor
PXR40 Microcontroller Reference Manual, Rev. 1
31-39