Global Memory Two Banks¶
This example of 2ddr is to demonstrate how to use multiple ddr and create buffers in each DDR.
KEY CONCEPTS: Multiple Banks
KEYWORDS: m_axi_auto_max_ports, sp, connectivity
This example demonstrates how buffers can be created in two different DDR(Global memory) banks.
By default, all the memory interfaces from all the kernels are connected to a single global memory bank. As a result, only one memory interface at a time can transfer data to and from the memory bank, limiting the performance of the kernel. If the FPGA contains only one DDR (or global) memory bank, this is the only option. However, some FPGA devices contain multiple DDR memory banks which allows us to customize the connections among the kernel memory interfaces and the DDR memory bank of a device by altering the default connection.
This example uses watermark application to demonstrate the utilization
of multiple DDRs for full bandwidth. Input image is placed into
Bank0
and kernel will read the input Image and write the output
image to Bank1
. Banks need to be specified using sp
tags in
apply_watermark.cfg file along with the port name and kernel name.
[connectivity]
sp=apply_watermark_1.input:DDR[0]
sp=apply_watermark_1.output:DDR[1]
EXCLUDED PLATFORMS:
All Embedded Zynq Platforms, i.e zc702, zcu102 etc
All Versal Platforms, i.e vck190 etc
Alveo U30
Alveo U50
Alveo U55
Samsung SmartSSD Computation Storage Drive
Samsung U.2 SmartSSD
X3 Compute Shell
All NoDMA Platforms, i.e u50 nodma etc
DESIGN FILES¶
Application code is located in the src directory. Accelerator binary files will be compiled to the xclbin directory. The xclbin directory is required by the Makefile and its contents will be filled during compilation. A listing of all the files in this example is shown below
data/golden.bmp
src/apply_watermark.cpp
src/host.cpp
Access these files in the github repo by clicking here.
COMMAND LINE ARGUMENTS¶
Once the environment has been configured, the application can be executed by
./gmem_2banks -x <apply_watermark XCLBIN> -i REPO_DIR/common/data/xilinx_img.bmp -c ./data/golden.bmp