What is the actual meaning of Frame Size and Actual Size explained in the Memory Map Table?

Hi TI,

I am using TMS570LC4357.

In TRM, Memory map Table contains two columns Frame Size and Actual Size (Shown Below).

Here Actual L2 SRAM size is 512kB, but it should be 4MB.

Because,

Each address location has 8-bits. So from calculation,

Total memory available = (0x083FFFFF - 0x08000000) = 0x003FFFFF = 4194303 bytes = 4MB.

4MB of memory should be available for SRAM space. But TRM says we have only 512kB of memory is there to use. So only I've this question.

Why 4MB of memory is kept away from usage?

Please anybody clarify me.

Thanks in advance.

Regards,

Karthikeyan Kasi Vishwanathan.