Embedded Design Handbook

ID 683689
Date 8/28/2023
Public
Document Table of Contents

3.5.2.1. Advantages

On-chip memory is the highest throughput, lowest latency memory possible in an FPGA-based embedded system. It typically has a latency of only one clock cycle. Memory transactions can be pipelined, making a throughput of one transaction per clock cycle typical.

Some variations of on-chip memory can be accessed in dual-port mode, with separate ports for read and write transactions. Dual-port mode effectively doubles the potential bandwidth of the memory, allowing the memory to be written over one port, while simultaneously being read over the second port.

Another advantage of on-chip memory is that it requires no additional board space or circuit-board wiring because it is implemented on the FPGA directly. Using on-chip memory can often save development time and cost.

Finally, some variations of on-chip memory can be automatically initialized with custom content during FPGA configuration. This memory is useful for holding small bits of boot code or LUT data which needs to be present at reset.