OMAPL138B-EP: LDR instruction clock cycles in arm

Part Number:OMAPL138B-EP

Hello,

Why an LDR instruction in omap l138 processor arm core takes 37 clock cycle in case of an address loaded in internal ram and 67 clock cycles for external ram.Is it natural,then why it takes that much clocks. I tried with different codes and observe the same all the time.