PDATS Trace

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PDATS Trace

PDATS Trace captures all the read/write access from CPU to memory. DMA access is not captured as part of this trace.

What is PDATS

PDATS (Packed Differential Address and Time Stamp) is a information-lossless trace compression scheme that can reduce both storage space and access time by an order of magnitude or more, compared to ASCII-format traces, without discarding either references or inter-reference timing from the original trace.

Supported Configuration

Supported on all C64x+ based single-core devices.
C6416 Cycle Accurate Simulator
C6416 Functional Simulator
TCI6616/C6670/TCI6608/C6678 Device simulator

Usage

Enabling PDATS Trace

PDATS Trace is enabled through the simulator configuration . Trace collection should be started, halted & resumed during simulation through GEL commands. This is important to note. We enable it via the configuration file, but the actual starting, and stopping trace collection is done after the simulator has been initialized, and an executable file loaded on it.

Configuration File Changes

Follow the steps to enable PDATS trace in simulator configuration file.

Step 1: Open CCSetup and select the simulator.
Step 2: Identify the simulator configuration file of the selected simulator. Check the right pane of CCSetup or click the modify properties to show the configuration file path.
Step 3: Open the simulator configuration file & search for DSP keyword. Next to DSP key is the module name of the CPU. (Ex: DSP C64xplus;)
Step 4: Search for END <Module name> and add the module profile given below above that line. (Ex: END C64xplus;)

MODULE PDATS_TRACE;
ACCESS_SIZE_TRACE ON;
TIMESTAMP_WITH_MEMSTALLS OFF;
END PDATS_TRACE;

Note

ACCESS_SIZE_TRACE - [ON/OFF]. This option enables the generation of “access width” in the PDATS format.
TIMESTAMP_WITH_MEMSTALLS -[ON/OFF]. This option is provided to select either
- [OFF] CPU only cycles (excludes memory system stalls)
- [ON] Total cycles (includes memory system stalls)

For C6416 Cycle Accurate simulator - add the following line to enable PDATS trace.

PDATS_TRACE ON;

Dynamic Start-Stop

PDATS Traces are started, halted & resumed during simulation. This support is enabled via GEL commands

Resume Trace collection - GEL_DriverString("START_PDATS_COLLECTION")
Halt/Stop Trace collection - GEL_DriverString("STOP_PDATS_COLLECTION")

On Code Composer Studio V4 (CCSv4), the GEL_DriverString commands could be provided to the simualtor through the scripting console(View->scripting console). In the console window, enter eval("GEL_DriverString(\"START_PDATS_COLLECTION\")") to feed in pdats start command for eg..

There could be multiple start-stop points throughout the simulation run. The trace file has a .pdats extension and will be generated in the COFF file path, with <coff_file_name>.pdats