Texas Instruments Corporation

Texas Instruments Incorporated Deutschland, Gmbh

Manisha Agarwala

John M Johnsen

Lewis Nardini

Gary L Swoboda

Oliver P Sohm

Maria B H Gill

Bryan Joseph Thome

Brian Cruickshank

Shivaling S Mahant-Shetti

Jose Luis Flores

Mahesh Madhukar Mehendale

Robert J Landers

Mark G Harward

Timothy David Anderson

Neil Common

Trace data streams are generated for tracing target processor activity. Various trace data streams are synchronized using markers called sync points. The sync points provide a unique identifier field and a context to the data that will follow it. All trace data streams may generate a sync point with this unique identifier. These unique identifiers allow synchronization between multiple trace data streams. When multiple trace data streams are on, it is possible that the data input rate may be higher than the data output rate. If synchronization is lost in such a case, there must be a scheme to resynchronize the streams. This invention is a technique for this needed resynchronization.

Maintaining coherent synchronization between data streams on detection of overflow

A method and system of inserting marker values used to correlate trace data as between processor cores. At least some of the illustrative embodiments are integrated circuit devices comprising a first processor core, a first data collection portion coupled to the first processor core and configured to gather data comprising addresses of instructions executed by the first processor core, a second processor core communicatively coupled to the first processor core, and a second data collection portion coupled to the first processor core and configured to gather data comprising addresses of instructions executed by the second processor core. The integrated circuit device is configured to insert marker values into the data of the first and second processor cores which allow correlation of the data such that contemporaneously executed instruction are identifiable.

Memory time stamp register external to first and second processors

Stored program writing stall information when a processor stalls waiting for another processor

Data streams are generated for tracing target processor activity. When multiple streams are on, they are written at different times into their individual FIFO. It is possible that for a specific stream, the length and fields of the data that should be exported vary. This invention is a scheme to send out only the relevant fields.

Dynamic data trace output scheme

In the case of tracing processor activity and generating data streams multiple triggers can be generated at the same time. The issue is further complicated in a protected pipeline where certain locations are considered as in illegal instruction boundary. During those cycles certain information is invalid and cannot be transmitted to the user. Thus a received trace trigger cannot begin. This invention resolves all ambiguities related to multiple triggers so that the user has a known predictable behavior based on the setup of the triggers.

Trigger ordering for trace streams when multiple triggers accumulate

When events are traced, the timing stream is used to associate events with instructions and indicate pipeline advances precluding the recording of stall cycles. Additional information is needed in the trace stream to identify an overlay whose execution of code is in a system where overlays or a memory management unit are used. In the case of PC trace, additional information is added when the memory system contents is changed. Information describing the configuration change is inserted into the export streams by placing this information in a message buffer. As long as a message word is available for output, it becomes the next export word as the output of message words is continuous.

Embedding event information in the timing stream

A method of trace collection in a data processor begins trace data collection even if a trace trigger is received during an interval when a central processing unit is stalled. Trace data collection is deferred if a trace trigger is received during an interval of an invalid instruction boundary until a valid instruction boundary.

Precise detection of triggers and trigger ordering for asynchronous events

A method and system of indexing into trace data based on entries in a log buffer. At least some of the illustrative embodiments are methods comprising executing a traced program on a target device. The traced program writes entries to a log buffer within the target device, and the traced program also contemporaneously writes an index value for each entry to a register. The index value written to the register becomes part of trace data regarding the traced program and correlates each entry to a respective portion of the trace data. Using the information one may either or both: display on a display device a portion of the trace data (the portion selected based on selecting an entry from the log buffer); or display on the display a portion of the log buffer (the portion selected based on selecting an entry from the trace data).

Method and system of indexing into trace data based on entries in a log buffer

A system comprises a circuit configured to execute instructions and output event data corresponding to the execution of the instructions. The system also comprises a monitoring device coupled to the circuit. The monitoring device receives information about said event data. The event data comprises event data selected from a group consisting of memory events and external events.

Monitoring of memory and external events

A saturating count counts received event signals up to a first predetermined number. An overflow counter counts overflows up to a second predetermined number. The counter indicates overflow when the overflow count is non-zero and saturates and stops counting at a maximum count when the overflow count reaches the second predetermined number. The counter can be read via a register read operation. The sum of the sum of the first predetermined number of bits and the second predetermined number of bits being an integral multiple of 8 bits.

Reporting a saturated counter value

A method and system of identifying overlays used by a program. The overlays may be executable overlays (e.g., overlay programs and dynamically linked library programs), or the overlays may be data sets. Depending on the number of overlays and/or the type of information used to identify the overlays, an indication of the identity of the overlays may be written to a register (whose contents are inserted into the trace data stream), or the indication may comprise an entry in a log buffer and an index value written to the register (again whose contents are inserted into the trace data stream, and where the index value identifies the entry in the log buffer).

Method and system of identifying overlays used by a program

Navigating trace data. A traced program, or the operating system responsible for the traced program, writes index values to a particular hardware location, which index values become part of the trace data by operation of hardware devices in the target system. A debug-trace program (executed either in an attached host computer or as an embedded debugger) uses the index values to assist the user of the debug-trace program in navigating to particular portions of the trace data based on the index values.

Navigating trace data

Code will switch to secure code via an exception only. All PC and data trace will be turned off during secure code. This will occur regardless of trace being in standard trace mode or event profiling mode. Timing, if on, will switch to standby mode. On return from the secure code, the switches that were already on will switch back and turn on. The address reported in the end sync point will be the address 0x01. Since this is an illegal address, this information is sufficient to indicate an end sync point was caused in secure code.

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Richardson, TX, United States of America

Manisha Agarwala