Delay Effect Implementation

Sun, 14 Jun 2026 19:40:36 +0200

Introduction

While keeping sight of my target when doing this project, there were some components on the Arty that I don’t really know how to use. One of this was the DRAM mounted on the board. Hence, I wanted to implement the most obvious effect that needs some kind of memory of previous samples.

Basically the delay will take at some point of the chain the samples at a rate of 48KHz, store them in a circular buffer in RAM and set up a memory pointer for reading at some distance of the writing pointer in such a way that the reading is yielding back audio from the past. The maths for this are quite simple in the end, with a sampling rate of 48KHz every memory address of distance between read and write adds ~20.8 microseconds of delay. So let’s say I want a delay of up to ~2 seconds we will need 192000 bytes of memory. It’s honestly not even that much when the mounted memory is 1GByte.

Ddr on Daniel Hacks It

Delay Effect Implementation

Introduction