Due to the parameterizable nature of the AXI CDMA, throughput is best measured as a percentage of the AXI4 bus bandwidth available to the AXI CDMA (as shown in the following table). This available bus bandwidth is a function of the clock frequency of the AXI4 bus and the parameterized data width of the AXI CDMA. The other parameter affecting throughput is the value of Max Burst Length of the AXI CDMA.
In general, the bigger value assigned increases the realized throughput of the AXI CDMA. However, larger burst lengths can be detrimental to other components of a user system design, causing lower system performance.
| C_M_AXI_BURST_LEN | Test Packet Size | AXI4 Frequency | Observed Bus Bandwidth Utilization by AXI CDMA |
|---|---|---|---|
| 16 | 9,000 bytes | 150 MHz | 70% |
| 64 | n | 150 MHz | up to 99% |