07-01-2014 10:06 PM
I use one GP AXI Master Port to extend IO by adding AXI Interconnect IP and AXI GPIO IP. I test AXI GPIO rate, only 2MHz-3MHz.
In SDK, using code below
XGpio_DiscreteWrite(&LED_Ptr, 1, 0xffffffff);
XGpio_DiscreteWrite(&LED_Ptr, 1, 0x00000000);
When I set FCLK_CLK0 100MHZ, GPIO rate is about 2.3MHz.If FCLK_CLK0 200MHZ, GPIO rate is about 3.6MHz.
I think it is too slow. What is the max rate for AXI GPIO? How to config ZYNQ to max AXI GPIO rate? Thanks!
07-07-2014 03:35 PM
I'm also experimenting with the AXI GPIO. I saw your post in the Zedboard forum where someone suggested using a function inside of XGpio_DiscreteWrite. I thought this was a good idea for a software approach.
I cannot find the function definition for XGpio_DiscreteWrite. I'm unsure how to find it. The documentation seems to be in HTML format. Maybe my program to open it (Chrome) isn't handling it correctly.
If I were going to blink LEDs at a certain rate (I am trying to, actually) I would tie the LEDs to a clock divider which was connected to the fabric clock.
07-07-2014 03:57 PM
The function XGpio_DiscreteWrite is included in the following driver code xgpio.c
11-25-2014 09:49 AM
10-29-2015 09:03 PM
What is the reason we can't push it?
I am writing a device driver to update the display which is 320 x 240 x 24 bit. So if it's 2.5MHz, then my application will do nothing but update the display assuming 30 fps.
10-29-2015 09:22 PM
It's a fundamental limitation of the AXI GP ports. If you want high speed, you need an AXI master in PL to read the frame buffer from the ddr itself.