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
Based on the observations made in Section 7.2, Table 37 lists the factors that affect the IPU Cortex-M4 CPU performance.
Factors | Impact | General Recommendation |
---|---|---|
Source/Destination Memory | The transfer speed depends on SRC/DST memory bandwidth. | Know the nature of the source and destination memory, specifically the frequency of operation and the bus width. |
Transfer Size versus Cache Size | Larger data buffers written to than the cache size introduces a cache line write back along with the cache line reads for write allocate cache policy. | Expect drop in performance when the data buffer size written to is larger than the cache size. |
Cache ability | Transfer speed depends on Unicache enable/disable. | Enable Unicache to get performance boost. |
Cache Policy | Transfer speed depends on cache policy; write-back versus write-through and write-allocate versus no-write allocate. | Use write-through, no-write allocate policy to get more transfer speed. |
Maximizing cache line reuse | Improves the CPU RD-WR performance. | The same memory locations within a cached line should be reused as often as possible. Either the same data can be reread or new data written to already cached locations so that subsequent reads will hit. |
Eviction of a line | Avoiding eviction of a line as long as it is being reused improves the CPU RD-WR performance. |