• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 29 subscribers
  • Views 571 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

Original question:

CCS: TMS570LC4357 - DMA test : RAM access, HW Trigger

CCS: Ram speed by MPU setting and MPU regions

MINWOO LIM
Expert 1200 points
Other Parts Discussed in Thread: TMS570LC4357, HALCOGEN

Tool/software: Code Composer Studio

I use TMS570LC4357 board. I have questions about MPU settings.

First, I want to use DMA access in RAM. So, I set MPU setting write-through by HalCoGen application.

1. I wonder there are RAM speed difference between write-back and write-through (because write-back write in cache memory, but write-through write in ram and cache memory )

Second, the MPU regions - In technical documatation. There are 16 regions of MPU which set environment of the RAM area. 

2. I want to know why the regions is divided. and setting method (I use HalCoGen application, There is no way in C code? )

Thanks and Regards, Minwoo.

  • 0
    TI__Mastermind 49120 points

    Hi Minwoo,

    A write-back cache will result in better performance versus a write-through cache configuration. This is true in general, and makes the cache / main RAM coherency considerations more complex. If you have other bus masters accessing parts of the main RAM, then you need to consider defining those regions as either write-through or even uncacheable from the CPU's point of view.

    This is the reason that multiple MPU regions are supported for the CPU. It allows you to define the required attributes (CPU perspective) for the entire accessible memory.

    HALCoGen generates the correct assembly routines for configuring the MPU for the Cortex-R5F CPU. These system control coprocessor register configurations are possible only using ARM assembly, and I highly recommend generating the routines using HALCoGen.

    Regards, Sunil