Before moving deeper into network setting and NIMU driver tuning, it is good to understand if the throughput is limited by the CPU load, which is probably 100% busy? Such can be answered by using Unified Instrumentation Architecture (UIA) module for CPU load measurement. The major steps include:

Figure 4-3 Adding UIA Module Into CCS Project

1. Add the below configuration into the .cfg file. The SYSBIOS has a default CPU speed info which needs to be updated with the real CPU speed as well:

   BIOS.cpuFreq.lo = 1000000000;  /*1GHz CPU*/
   
   var LoggingSetup = xdc.useModule('ti.uia.sysbios.LoggingSetup');
   LoggingSetup.loadLogging = true;
   LoggingSetup.loadLoggerSize = 32768;
   LoggingSetup.mainLoggerSize = 32768;
   LoggingSetup.sysbiosLoggerSize = 32768;
   LoggingSetup.sysbiosSemaphoreLogging = true;
   LoggingSetup.loadTaskLogging = true;
   LoggingSetup.loadSwiLogging = true;
   LoggingSetup.loadHwiLogging = true;
   LoggingSetup.enableTaskProfiler = true;
   LoggingSetup.eventUploadMode = LoggingSetup.UploadMode_JTAGSTOPMODE;

2. Enable the UIA measurement in CCS by selecting Tools → RTOS Analyzer → Load Analysis:
   Figure 4-4 UIA Analysis Configuration
3. Run the test.
4. Halt CPU to collect the CPU load graph. Below is an example with Tx throughput 61MB/s followed by Rx throughput 59MB/s. The CPU load is 55% and 68%, respectively, so there is still CPU processing power left.
   Figure 4-5 A15 CPU Load Under FTP Transmitting and Receiving
5. Note that the UIA module adds a little bit overhead as every context switch is being timestamped to get more accurate CPU load number. Remove the UIA code in the .cfg file once the measurement is performed.