Fast GPIO output with TIRTOS

Equipment:

            ICEv2 board,

            CCSv6 vs 6.0.1.00040,

            TI XDS100v2 USB Emulator,

            Windows7,

            am335x_sysbios_ind_sdk_1.1.0.6

            NDK 2.24.1.18

            NDK's NSP 1.10.2.09 not activated

            SYSBIOS 6.40.3.39

            Compiler TI v5.1.10

            Project: 'standalone Ethernet switch' derived from the EthernetIp example of the SDK,

                         PRUSS for Ethernet access

Hi,

 some time ago I had BeagleBoneBlack project that was able to change the level of  an GPIO output every 40ns.

The condition was to have these 2 statements right at the beginning of main():

      MMUConfigAndEnable();

      CacheEnable(0x03);  // Instruction, Data and Unified Cache at all levels

Now with TIRTOS it is only possible to change it every 215ns, which is too slow for this project.

I did not use the statements above and try to avoid Starterware functions (double definition of MMUInit() for instance).

Instead MMUInit(applMmuEntries) is called, which came with the example code. In the .cfg file “Add the Cache-Modul” is checked (  Enable Cache and Enable L2-cache ways at startup). Surprisingly there is no “Cache.enableCache = true;” in the .cfg script.

What I would need is a hint how to speed up that GPIO3 output again. The processor frequency is now at 550MHz. Is there a way to raise it? Or am I missing something principal?

All comments are very much appreciated.

Thank you.

Regards,

Martin H.