Error Messages - STMicroelectronics SPC572L series Reference Manual

RM0400
66.10

Error messages

Error messages are enabled whenever the debug logic is enabled. There are two conditions
that will produce an error message, each receiving a separate error type designation:
•
A message is discarded due to contention with other (higher priority) message types.
These errors will have an Error Type value of 1.
•
The message queue overruns. After the queue is drained, an error message is
enqueued with an error code that indicates what types of messages were discarded
during the interim. These errors will have an Error Type value of 0.
Note: The OVCR Register can be used in order to alleviate potential overrun situations.
Error information is messaged out in the following format (also see
Table 1073):
66.11 Ownership trace
This section details the ownership trace features of the Nexus 3 module.
66.11.1 Overview
Ownership trace provides a macroscopic view, such as task flow reconstruction, when
debugging software written in a high level (or object-oriented) language. It offers the highest
level of abstraction for tracking operating system software execution. This is especially
useful when the developer is not interested in debugging at lower levels.
66.11.2 Ownership Trace Messaging (OTM)
Ownership trace information is messaged via the auxiliary port using an Ownership Trace
Message (OTM). Core (e200z215An3) processors contain a PowerISA 2.06 defined
"Process ID" register within the CPU. It is updated by the operating system software to
provide task/process ID information. The contents of this register are replicated on the pins
of the processor and connected to Nexus. The Process ID (PID) register value can be
accessed using the mfspr/mtspr instructions.
Note: The CPU includes a Process ID register (PID0), thus the Nexus UBA functionality is not
implemented.
In addition, to decouple trace information from the PID0 register and to provide a full
independent 32-bit process ID for debug use, the Nexus PID Register (NPIDR) may be used
instead of PID0 to provide OTM process ID information. It is updated by the operating
system software to provide task/process ID information. The Nexus Process ID (NPIDR)
register value can be accessed using the mfspr/mtspr instructions. This register is
accessible in user or supervisor mode.
Figure 1160. Error message format
(6 bits)
Error Code
Fixed length = 20 bits
DocID027809 Rev 4
e200z215An3 Nexus 3 Module
(4 bits) (4 bits)
Error Type Src. Proc.
Table 1072 and
(6 bits)
TCODE (001000)
1949/2058
1982