Data

Versal ACAP Technical Reference Manual (AM011)

Document ID
AM011
Release Date
2022-04-26
Revision
1.4 English

The interconnect includes the AXI and APB interface protocols. The AXI data width can be 32, 64, or 128 bits. The APB protocol is used for the 32-bit programming interfaces and low-bandwidth data ports.

The smallest data transaction is a single 32-bit word. The largest transaction is a 128-bit data word with a burst of 256 data cycles (4 KB burst size).

  • AXI: Sources can burst up to 256 words
  • APB: Receive single 32-bit data word
  • NPI: Receive burst of 32-bit data words
  • AXI: Destinations can only receive up to 16 words

Transaction Adaptation

The interconnect manages transaction requests. When the source and destination have a different data width or burst length, the transaction is modified, including breaking up a long burst into shorter bursts.

When an AXI transaction includes a 256-word burst, but the destination only supports 16-word bursts, the interconnect breaks the transaction into 16-word bursts with the proper data width for the destination interface.