The Windows software package includes a document with instructions on how to run the application. You can also use the software driver to measure and display the performance achieved for the transfers. The DMA operation completes when the Done bit is set and the performance is calculated. This module is included in the IP Core to facilitate the customization of descriptor handling. Depending on what already exists.

Uploader: Malajind
Date Added: 26 December 2008
File Size: 63.70 Mb
Operating Systems: Windows NT/2000/XP/2003/2003/7/8/10 MacOS 10/X
Downloads: 45341
Price: Free* [*Free Regsitration Required]

PCI Express DMA Reference Design Using External Memory

Control in Descriptor Controller. The completer can split the Completion into multiple completion packets. I do this part all of the time. Optionally, you can use an external descriptor controller for your application. The first figure shows the requester waiting for the completion before issuing the subsequent requests. It results in lower throughput. When I’m done with this, I would love to release an example for people, but that might be difficult due to company rules. The descriptor controller can also be external to the DMA module.

I’m more a micro processor sort of guy, but I’ve dabbled.

There are separate credits for headers and payload data. It transfers data between an external memory and host system memory. They do have an example driver available for one of their other boards, but it isn’t useful for our use case it’s an OpenCL driver and doesn’t provide easy, direct access to internal registers. The read throughput depends on the delay between the time when sma Application Layer issues a Memory Read Request and the time the completer takes to return data.


Share This Page

Set the number of descriptors. You will get the following error message when you install the driver for the first time: Linux drivers are generally a bit high level for me. The legal range is descriptors. Made the following changes: Software allocates free space in the system memory for the data to be moved to and from the latera memory by the DMA. The reference design has the following hardware and software requirements: Is there an easy way to define a virtual address space for the device to access such that on the Linux side I don’t have to care where in memory it is stored?

Enable or disable read DMA. The theoretical maximum throughput is calculated using the following formula:. Type your super user password. In the directory that you created, login as root by typing su.

This computer is referred as computer number 2. Da much everything I’ve done before has been bare-metal or a RTOS when it comes to applications like this.


Software completes the following steps to specify and initiate a DMA operation:. Email Required, but never shown. I would recommend purchasing the book if you plan on doing much kernel module development. Programming specifies the base address of the descriptor table which stores the descriptors in the system memory and the base address of the FIFO which is going to store the descriptors in the FPGA fabric domain.

The completer returns a Completion with Data. After determining the maximum TLP payload for the current system, software records that value in altfra Device Control register.

Step one, you’ve got a specific kernel version to use. The maximum throughput is 8 GBps x