On Chip RAM is slow after enabling MMU, and using external ram aborts

Hello All,

       I am using Omap3515 (Arm Cortex A8). Enabled I-Cache, D-Cache, Branch Prediction and MMU.

Issue 1:

But what I could notice is code region in external ram is executing faster than internal ram.

If I disable MMU, then access to internal ram is faster. It would be great, if someone explains this.

Issue 2:

And also I am getting a data abort, if I try to copy a frame buffer of 600KB from an external memory region to another external memory region.

Please find attached the MMU Page table

Thanks and regards,

Gopu