External Memory Interface Handbook Volume 3: Reference Material: For UniPHY-based Device Families

ID 683841
Date 3/06/2023
Public
Document Table of Contents

4.12. Initialization

The SDRAM controller subsystem has control and status registers (CSRs) which control the operation of the controller including DRAM type, DRAM timing parameters and relative port priorities. It also has a small set of bits which depend on the FPGA fabric to configure ports between the memory controller and the FPGA fabric; these bits are set for you when you configure your implementation using the HPS GUI in Platform Designer (Standard).

The CSRs are configured using a dedicated slave interface, which provides access to the registers. This region controls all SDRAM operation, MPFE scheduler configuration, and PHY calibration.

The FPGA fabric interface configuration is programmed into the FPGA fabric and the values of these register bits can be read by software. The ports can be configured without software developers needing to know how the FPGA-to-HPS SDRAM interface has been configured.