In the spec it is mentioned that AXI4 supports high-bandwidth, high-frequency and low-latency operation. How to justify this? What is the meaning of bandwidth in this context? What are the values of bandwidth and frequency? How they decide the operating frequency of any protocol ( like AXI, AHP, AHB etc )
In comparison to previous AMBA protocols, such as AHB, certain features of AXI4 give it advantages in these areas.
Bandwidth in this context would typically be measured as the amount of data transferred in a set time period (e.g. MB/s). AXI supports multiple outstanding transactions, which means that latency doesn't necessarily impact the bandwidth. It also support large data widths and has separate read and write channels which also help increase the bandwidth available.
AXI can support low latency operation in that a transaction can be completed within 2 cycles. Having outstanding multiple accesses also makes it appropriate for high latency systems.
The AMBA protocols do not have a defined frequency that they can run at, but certain features can make it easier to run a protocol at a higher frequency. For example, AXI does not have a strict relationship between channels, and so different amounts of registering can be placed on different channels in order to run the bus faster.
Thank you..And I didn't get the difference between bandwidth and data rate.
I don't believe the AMBA Specs draw any distinction between bandwidth and data rate. These terms are synonymous in this context.