• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 98 subscribers
  • Views 355 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

6457 "no-boot" setting

Bryan Busacco
Expert 1215 points
Other Parts Discussed in Thread: TMS320C6455

1) I an concerned about an answer I received on boot mode configuration for the C6457 DSP.  We would like to boot from ethernet or FLASH, and can use a jumper or dip switch on the board to make that selection.

I was told that If we want to use JTAG, we need to tie the boot mode pins to the "no-boot' configuration. I would like to verify this is true because the TMS320C6455 data sheet has a note 4 associated with the EMU0/1 mode pins:

(4) The C6455 DSP does not require external pulldown resistors on the EMU0 and EMU1 pins for normal or boundary-scan operation.

 

It seems unlikely that the two DSP's are different with respect to mode pin settings. I want to determine if connecting JTAG means that the 6457 DSP ignores the boot mode pins. If this is true, we can simplify the dip switches or jumpers required in the design to support ethernet boot, FLASH boot and JTAG.

Thanks,

 

Bryan Busacco.

  • 0
    TI__Guru* 84110 points

    Bryan Busacco said:
    The C6455 DSP does not require external pulldown resistors on the EMU0 and EMU1 pins for normal or boundary-scan operation.

    In the C6457 datasheet, there is a (3) by the EMU0 and EMU1 pins in the Terminal Functions table, but I could not find the note being referenced. The C6457 datasheet will probably be updated to put a similar statement as the one that you quote above from the C6455 datasheet.

    Bryan Busacco said:
    I want to determine if connecting JTAG means that the 6457 DSP ignores the boot mode pins.

    This is not the case. In fact, this would make some debug very difficult, such as debugging the boot ROM or debugging a system that boots from one of the active boot modes (not No-boot).

    The BOOTMODE[3:0] pins for the C6457 are mapped to GPIO[4:1] at device reset. These are the pins that you need to put jumpers on for boot mode selection. For a new board, I recommend having jumpers on all of the BOOTMODE pins, i.e. GPIO[4:1], or at least have DoNotPopulate resistor pads to ground and to 3.3V. When you are trying to find out if your board works, after the initial "smoke test", you definitely want to have No Boot available.

     

    If this answers your question, please click  Verify Answer  on this posting; if not, please reply back with more information to help us answer your question.