This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TM4C123GH6PZ: GPIO speed, DMA, AHB

Part Number: TM4C123GH6PZ

We are using TM4C123GH6PZ for 80MHZ pll lifted what is the GPIO frequency that the micro controller can work with? if we want to work with full speed 80Mhz should we configure the bus for AHB(DMA access) or can it work as basic IO port?

kindly share the example code for the above points in order to verify the same.

regards 

 

  • Using the CPU at 80Mhz with a very optimized code I achieved a transfer every 100nS (every 8 cycles). Using the uDMA can offload the CPU load but may not be faster depending on what the CPU is doing. The uDMA has a lower priority to accessing the bus than the CPU. I setup an example sending 256 bytes of data from RAM to 6 pins of GPIO port A (using AHB) and achieved a transfer every 50nS. In this case the CPU was doing nothing in a branch to self loop except at the end of the transfer to restart the uDMA

    I have attached the project in a .zip file. Use Code Composer Studios "file", "Import" feature to add this project to your workspace.

    /cfs-file/__key/communityserver-discussions-components-files/908/GPIOA_5F00_AHB_5F00_uDMA.zip