SPRAC21A June   2016  – June 2019 OMAP-L132 , OMAP-L138 , TDA2E , TDA2EG-17 , TDA2HF , TDA2HG , TDA2HV , TDA2LF , TDA2P-ABZ , TDA2P-ACD , TDA2SA , TDA2SG , TDA2SX , TDA3LA , TDA3LX , TDA3MA , TDA3MD , TDA3MV

 

  1.   TDA2xx and TDA2ex Performance
    1.     Trademarks
    2. 1  SoC Overview
      1. 1.1 Introduction
      2. 1.2 Acronyms and Definitions
      3. 1.3 TDA2xx and TDA2ex System Interconnect
      4. 1.4 Traffic Regulation Within the Interconnect
        1. 1.4.1 Bandwidth Regulators
        2. 1.4.2 Bandwidth Limiters
        3. 1.4.3 Initiator Priority
      5. 1.5 TDA2xx and TDA2ex Memory Subsystem
        1. 1.5.1 Controller/PHY Timing Parameters
        2. 1.5.2 Class of Service
        3. 1.5.3 Prioritization Between DMM/SYS PORT or MPU Port to EMIF
      6. 1.6 TDA2xx and TDA2ex Measurement Operating Frequencies
      7. 1.7 System Instrumentation and Measurement Methodology
        1. 1.7.1 GP Timers
        2. 1.7.2 L3 Statistic Collectors
    3. 2  Cortex-A15
      1. 2.1 Level1 and Level2 Cache
      2. 2.2 MMU
      3. 2.3 Performance Control Mechanisms
        1. 2.3.1 Cortex-A15 Knobs
        2. 2.3.2 MMU Page Table Knobs
      4. 2.4 Cortex-A15 CPU Read and Write Performance
        1. 2.4.1 Cortex-A15 Functions
        2. 2.4.2 Setup Limitations
        3. 2.4.3 System Performance
          1. 2.4.3.1 Cortex-A15 Stand-Alone Memory Read, Write, Copy
          2. 2.4.3.2 Results
    4. 3  System Enhanced Direct Memory Access (System EDMA)
      1. 3.1 System EDMA Performance
        1. 3.1.1 System EDMA Read and Write
        2. 3.1.2 System EDMA Results
      2. 3.2 System EDMA Observations
    5. 4  DSP Subsystem EDMA
      1. 4.1 DSP Subsystem EDMA Performance
        1. 4.1.1 DSP Subsystem EDMA Read and Write
        2. 4.1.2 DSP Subsystem EDMA Results
      2. 4.2 DSP Subsystem EDMA Observations
    6. 5  Embedded Vision Engine (EVE) Subsystem EDMA
      1. 5.1 EVE EDMA Performance
        1. 5.1.1 EVE EDMA Read and Write
        2. 5.1.2 EVE EDMA Results
      2. 5.2 EVE EDMA Observations
    7. 6  DSP CPU
      1. 6.1 DSP CPU Performance
        1. 6.1.1 DSP CPU Read and Write
        2. 6.1.2 Code Setup
          1. 6.1.2.1 Pipeline Copy
          2. 6.1.2.2 Pipeline Read
          3. 6.1.2.3 Pipeline Write
          4. 6.1.2.4 L2 Stride-Jmp Copy
          5. 6.1.2.5 L2 Stride-Jmp Read
          6. 6.1.2.6 L2 Stride-Jmp Write
      2. 6.2 DSP CPU Observations
      3. 6.3 Summary
    8. 7  Cortex-M4 (IPU)
      1. 7.1 Cortex-M4 CPU Performance
        1. 7.1.1 Cortex-M4 CPU Read and Write
        2. 7.1.2 Code Setup
        3. 7.1.3 Cortex-M4 Functions
        4. 7.1.4 Setup Limitations
      2. 7.2 Cortex-M4 CPU Observations
        1. 7.2.1 Cache Disable
        2. 7.2.2 Cache Enable
      3. 7.3 Summary
    9. 8  USB IP
      1. 8.1 Overview
      2. 8.2 USB IP Performance
        1. 8.2.1 Test Setup
        2. 8.2.2 Results and Observations
        3. 8.2.3 Summary
    10. 9  PCIe IP
      1. 9.1 Overview
      2. 9.2 PCIe IP Performance
        1. 9.2.1 Test Setup
        2. 9.2.2 Results and Observations
    11. 10 IVA-HD IP
      1. 10.1 Overview
      2. 10.2 H.264 Decoder
        1. 10.2.1 Description
        2. 10.2.2 Test Setup
        3. 10.2.3 Test Results
      3. 10.3 MJPEG Decoder
        1. 10.3.1 Description
        2. 10.3.2 Test Setup
        3. 10.3.3 Test Results
    12. 11 MMC IP
      1. 11.1 MMC Read and Write Performance
        1. 11.1.1 Test Description
        2. 11.1.2 Test Results
      2. 11.2 Summary
    13. 12 SATA IP
      1. 12.1 SATA Read and Write Performance
        1. 12.1.1 Test Setup
        2. 12.1.2 Observations
          1. 12.1.2.1 RAW Performance
          2. 12.1.2.2 SDK Performance
      2. 12.2 Summary
    14. 13 GMAC IP
      1. 13.1 GMAC Receive/Transmit Performance
        1. 13.1.1 Test Setup
        2. 13.1.2 Test Description
          1. 13.1.2.1 CPPI Buffer Descriptors
        3. 13.1.3 Test Results
          1. 13.1.3.1 Receive/Transmit Mode (see )
          2. 13.1.3.2 Receive Only Mode (see )
          3. 13.1.3.3 Transmit Only Mode (see )
      2. 13.2 Summary
    15. 14 GPMC IP
      1. 14.1 GPMC Read and Write Performance
        1. 14.1.1 Test Setup
          1. 14.1.1.1 NAND Flash
          2. 14.1.1.2 NOR Flash
        2. 14.1.2 Test Description
          1. 14.1.2.1 Asynchronous NAND Flash Read/Write Using CPU Prefetch Mode
          2. 14.1.2.2 Asynchronous NOR Flash Single Read
          3. 14.1.2.3 Asynchronous NOR Flash Page Read
          4. 14.1.2.4 Asynchronous NOR Flash Single Write
        3. 14.1.3 Test Results
      2. 14.2 Summary
    16. 15 QSPI IP
      1. 15.1 QSPI Read and Write Performance
        1. 15.1.1 Test Setup
        2. 15.1.2 Test Results
        3. 15.1.3 Analysis
          1. 15.1.3.1 Theoretical Calculations
          2. 15.1.3.2 % Efficiency
      2. 15.2 QSPI XIP Code Execution Performance
      3. 15.3 Summary
    17. 16 Standard Benchmarks
      1. 16.1 Dhrystone
        1. 16.1.1 Cortex-A15 Tests and Results
        2. 16.1.2 Cortex-M4 Tests and Results
      2. 16.2 LMbench
        1. 16.2.1 LMbench Bandwidth
          1. 16.2.1.1 TDA2xx and TDA2ex Cortex-A15 LMbench Bandwidth Results
          2. 16.2.1.2 TDA2xx and TDA2ex Cortex-M4 LMBench Bandwidth Results
          3. 16.2.1.3 Analysis
        2. 16.2.2 LMbench Latency
          1. 16.2.2.1 TDA2xx and TDA2ex Cortex-A15 LMbench Latency Results
          2. 16.2.2.2 TDA2xx and TDA2ex Cortex-M4 LMbench Latency Results
          3. 16.2.2.3 Analysis
      3. 16.3 STREAM
        1. 16.3.1 TDA2xx and TDA2ex Cortex-A15 STREAM Benchmark Results
        2. 16.3.2 TDA2xx and TDA2ex Cortex-M4 STREAM Benchmark Results
    18. 17 Error Checking and Correction (ECC)
      1. 17.1 OCMC ECC Programming
      2. 17.2 EMIF ECC Programming
      3. 17.3 EMIF ECC Programming to Starterware Code Mapping
      4. 17.4 Careabouts of Using EMIF ECC
        1. 17.4.1 Restrictions Due to Non-Availability of Read Modify Write ECC Support in EMIF
          1. 17.4.1.1 Un-Cached CPU Access of EMIF
          2. 17.4.1.2 Cached CPU Access of EMIF
          3. 17.4.1.3 Non CPU Access of EMIF Memory
          4. 17.4.1.4 Debugger Access of EMIF via the Memory Browser/Watch Window
          5. 17.4.1.5 Software Breakpoints While Debugging
        2. 17.4.2 Compiler Optimization
        3. 17.4.3 Restrictions Due to i882 Errata
        4. 17.4.4 How to Find Who Caused the Unaligned Quanta Writes After the Interrupt
      5. 17.5 Impact of ECC on Performance
    19. 18 DDR3 Interleaved vs Non-Interleaved
      1. 18.1 Interleaved versus Non-Interleaved Setup
      2. 18.2 Impact of Interleaved vs Non-Interleaved DDR3 for a Single Initiator
      3. 18.3 Impact of Interleaved vs Non-Interleaved DDR3 for Multiple Initiators
    20. 19 DDR3 vs DDR2 Performance
      1. 19.1 Impact of DDR2 vs DDR3 for a Single Initiator
      2. 19.2 Impact of DDR2 vs DDR3 for Multiple Initiators
    21. 20 Boot Time Profile
      1. 20.1 ROM Boot Time Profile
      2. 20.2 System Boot Time Profile
    22. 21 L3 Statistics Collector Programming Model
    23. 22 Reference
  2.   Revision History

6.2 DSP CPU Observations

Figure 24 gives the average DSP bandwidth in MBps (y-axis) measured for the different functions introduced above, for different data sizes of 16 KiB, 64 KiB, 128 KiB, 256 KiB, and 8 MiB (x-axis) for the L1D and L2 cache size of 32 K and 128 K, respectively. The given bandwidth was measured with prefetch enable, MMU off, and L1D write back policy enabled. Each cache line fetch for 128 bytes is actually two VBUS commands for 64 bytes.

dsp_cpu_read_write_performance_different_data_sprac21.pngFigure 24. DSP CPU Read and Write Performance With Different Data Sizes to DDR

For a memcpy() type operation, there are both reads and writes. Furthermore, the L2 cache write-allocates. For buffer sizes that fit entirely within L2, the traffic at the MDMA boundary will look like two streams of reads. For buffer sizes larger than L2, there is a third stream consisting of victim writes. That’s why the numbers start falling off as the data sizes get above 128K. The reads do not show this trend as the cache lines do not become dirty and the cache would not perform a write back of the cache line when the data sizes are larger than the cache line.

The L2 pipeline functions generate more L2 cache line fetches and write backs in a shorter time span leading to a higher throughput.

The L2 memory controller conveys to the XMC whether a given address range is pre-fetchable. This information comes directly from the “PFX” field in the corresponding MAR register. Figure 25 shows the effect of pre-fetch ON versus OFF for DDR transfers with MMU off, MDMA Posted writes and L1D write back policy enabled. The XMC pre-fetcher does not distinguish read-allocate from write-allocate; it will try to pre-fetch for either to speed things up as seen by the ~2x performance increase with pre-fetch ON versus OFF for both read and write streams.

impact_prefetch_enable_disable_cpu_perf_sprac21.pngFigure 25. Impact on Prefetch Enable versus Disable on CPU Performance

The DSP CPU read and writes throughput varies with the source and the destination of the buffer. Figure 26 shows the difference in bandwidth obtained when the data is transferred from DDR-to-DDR versus OCMC RAM-to-OCMC RAM for different data transfer sizes, with pre-fetch enabled, L2 cache size of 128K, and L1D of 32K with L1D write back policy enabled, MMU off and non-posted writes at the MDMA boundary for cached data.

impact_source_destination_memory_dsp_cpu_rdwr_sprac21.pngFigure 26. Impact of Source and Destination Memory on DSP CPU RD-WR Performance

A standalone memory management unit (DSP_MMU0) is included within the DSP1 (DSP1_MMU0) and DSP2 (DSP2_MMU0) subsystems boundaries. The DSP_MMU0 is integrated on the C66x CPU MDMA path to the device L3_MAIN interconnect. This provides several benefits including protection of the system memories from corruption by DSP1 and DSP2 accidental accesses. Figure 27 shows the effect of MMU off versus MMU on, with pre-fetch enabled, L2 cache size of 128K, and L1D of 32K with L1D write back policy enabled and posted writes at the MDMA boundary for cached data. The MMU adds to the latency in the path leading to slight drop in the throughput. (16MB Page size in TLB)

impact_mmu_enable_dsp_rdwr_performance_sprac21.pngFigure 27. Impact of MMU Enable on DSP RD-WR Performance

The C66x CorePac submits writes denoted as either “cacheable” or non-cacheable. Write accesses that are non-cacheable will be submitted as interconnect (L3_MAIN) non-posted writes; whereas, write accesses that are cacheable are submitted as interconnect posted writes based on the configuration of the C66xOSS_BUS_CONFIG. Figure 28 gives the comparison of the posted versus non-posted writes when measuring bandwidth of the cache flush operation while transferring data to DDR with pre-fetch enabled, L2 cache size of 128K, and L1D of 32K with L1D write back policy enabled.

impact_posted_nonposted_writes_dsp_cache_sprac21.pngFigure 28. Impact of Posted and Non-Posted Writes on DSP Cache Flush