Introduction

Xilinx libraries contain Video Direct Memory Access (VDMA) IP-core which can be used to transfer AXI4-Stream protocol based video stream to DDR memory and vice versa. Corresponding sub-components are S2MM (Stream to memory-mapped) also known as write channel and MM2S (Memory-mapped to stream) also known as read channel. Using both of them a video buffer can be implemented with optional crop and zoom features 1.

1

http://www.xilinx.com/support/documentation/ip_documentation/axi_videoip/v1_0/ug934_axi_videoIP.pd

Minimal hardware design

This is the last and the most complex example of what I have tried on the ZYBO.

High level block design for complete hardware pipeline

In this example we connect Omnivision OV7670 camera via modified capture block to AXI4-Stream Video compatible pipeline. The VDMA controller maintains a ring buffer in the DDR memory and transfers the frame data to these buffers as the frames are received by S2MM portion of the VDMA controller.

Address mapping with AXI Video Direct Memory Access

2

LogiCORE IP AXI Video Direct Memory Access v6.2