address space misunderstanding

Max Zhegulin

Intellectual 420 points

Hi all.

I have some misunderstanding with C5515 CS0 external memory address space.

According to DSP system user guide system memory section CSO starts from address 0x50000.

But according to sdram examples from ccs instalation directory external memory starts from address 0x28000.

Also in DMA user guide table 1 on page 11 column CPU start word address points to 0x28000 addres

Thanks!

max

over 14 years ago

0 Pratap Reddy M V over 14 years ago

Expert 2615 points

Hi Max,

0x50000 mentioed in the user guide is byte address. C5515 uses word addressing((byte address >> 1)), according to which 0x28000 is the starting address for external memory connected to CS0. You need to use word addressing in your programs to access memory of C5515.

Pratap.

0 Max Zhegulin over 14 years ago in reply to Pratap Reddy M V

Intellectual 420 points

t's little confused, because in linker scrip I should again use byte addressing.

Nevertheless, Pratap, thank you for your explanation.

0 Pratap Reddy M V over 14 years ago in reply to Max Zhegulin

Expert 2615 points

Hi Max,

You are right, byte addressing is used in linker command scripts. In case you are using BIOS configuration files(.tcf) for defining memory segments you have to use word addressing.

Pratap.

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address space misunderstanding