memory access during boot mode

anish menon

Other Parts Discussed in Thread: TMS320C6455

Is it possible to access any memory location during boot mode of the tms320c6455 ?

My scenario : from a host processor

1> put the dsp in hpi boot and tried to write into and read memory but tht didnt work. Tried to read the pci base reg which holds the vendor id but tht didnt help either.

2>put the dsp in no boot mode and tried to write and read but could not do that either.

Thank you

anish

over 14 years ago

0 Bill Taboada over 14 years ago

TI__Mastermind 42545 points

According to section 2.3.2 of the TMS320C645x/C647x DSP Bootloader Guide (SPRUEC6G) in HPI boot mode you should be able to load code and data directly into the DSP L2 memory. There are some section of L2 used by the bootloader that should be avoided. These are listed in section 2.1. Once the boot code has been loaded into memory the external host can access to the Host Port Interface Control register (HPIC) and set the DSPINT bit. While will cause the DSP to begin executing from the base of L2 memory. If you can not access L2 memory you should check the timing parameters of your interface to be sure that they meet the specification for HPI accesses.

0 Brad Griffis over 14 years ago in reply to Bill Taboada

TI__Guru*** 125430 points

A common mistake on the HPI is using byte addresses (i.e. the addresses listed in the data sheet and the map file) for accesses. The User Guide specifically says you must use word addresses (byte address right shifted by 2 bits). Here's a snippet from the guide:

0 anish menon over 14 years ago in reply to Brad Griffis

Intellectual 620 points

Hi Brad

Thank you for this information. But could you tell me which document has this? as in the no. I could not find it on the spruec6g ( boot loader) , the tms320c6455 main pdf nor the spru578c (HPI) .

Thank you

Anish

0 anish menon over 14 years ago in reply to anish menon

Intellectual 620 points

Hi Brad

Also wanted to confirm that can i read back from the memory during the boot mode? that is the internal RAM if i write to it ?

Because when i write to the HPIA 0x200000, and write any value to the HPID.

Then i write back 0x200000 to the HPIA again and try to read from the HPID, i get 0x200000

Whats the reason for this?

Thank you

Anish

0 Brad Griffis over 14 years ago in reply to anish menon

TI__Guru*** 125430 points

anish menon said:
I could not find it on the spruec6g ( boot loader) , the tms320c6455 main pdf nor the spru578c (HPI) .

That's not the correct HPI document. As a starting point for all c6455 documentation please refer to the product folder:

http://focus.ti.com/docs/prod/folders/print/tms320c6455.html

The correct HPI Guide (spru969) can be found there under Technical Documents. The warning I mentioned is shown in Section 8.5 "Host Port Interface Address Registers (HPIAR and HPIAW)".

0 Brad Griffis over 14 years ago in reply to anish menon

TI__Guru*** 125430 points

anish menon said:

Also wanted to confirm that can i read back from the memory during the boot mode? that is the internal RAM if i write to it ?

Because when i write to the HPIA 0x200000, and write any value to the HPID.

Then i write back 0x200000 to the HPIA again and try to read from the HPID, i get 0x200000

Whats the reason for this?

Yes, you can write and read from internal memory. Are you correctly using HPIAR and HPIAW? There are separate registers which I don't think you would have known in the document you were reading.

0 anish menon over 14 years ago in reply to Brad Griffis

Intellectual 620 points

Hi Brad

Thank you, that explains it, wrong document. It is really tough to understand which is the right and wrong one. So many documents.

Anish

0 Tai Nguyen over 14 years ago in reply to anish menon

TI__Expert 5955 points

Hi Anish,

Just as a second to Brad's points, please refer to section 2 of the TMS320C645x DSP HPI UG (SPRU969) since you are working with the TMS320C6455 device. There you will too find the same note that Brad mentioned above.

Thanks.

Tai

0 anish menon over 14 years ago in reply to Tai Nguyen

Intellectual 620 points

Thank you so much for all your help.

I had another question with regard to boot image creation :

http://focus.ti.com/general/docs/litabsmultiplefilelist.tsp?literatureNumber=sprab60

this is the software im using but i realize that its specific to C6000 architecture and i realize that on creation of the header file the address locations of the various units, some of them dont consider the issue of word address.

Is there another boot image creation program?

0 Brad Griffis over 14 years ago in reply to anish menon

TI__Guru*** 125430 points

You might want to use this cg_xml script:

http://e2e.ti.com/support/development_tools/compiler/f/343/p/99421/348928.aspx#348928

0 anish menon over 14 years ago in reply to Brad Griffis

Intellectual 620 points

Thank you so much Brad, help much appreciated :)

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memory access during boot mode