• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 98 subscribers
  • Views 515 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.

UART

Qing Chang
Intellectual 280 points
Other Parts Discussed in Thread: DM3730

Hi!

I've read "Sleep mode...... can be achieved only when the UART is set in modem mode" on page 2926 of AMDM37x ?Technical Reference Manual.pdf(SPRUGEN4R).

1) I'm wondering what the "modem mode" is?

2) And if the UARTs can not sleep, can I wake the DM3730 up throught  one of the UARTs?

I've read "Stacked modem(not in standalone configuration)" on page 2404 of the above document,

3) What does the phrase "stacked modem" exactly mean?

4) What does the phrase "standalone configuration" exactly mean?

5) I can't find any modem subsystem on DM3730, so whether there is  a MODEM_INTC on DM3730?

Many thanks!

  • 0
    TI__Guru 65405 points

    Hi Qing Chang,

    The term UART "modem mode" means that the UART is connected to a modem.

    If the UART subsystem can not go sleeping then the whole system is not sleeping.

    You can get some clarifications about "stacked modem" from ..linux/arch/arm/mach-omap2/control.c file comments and functions at the link:

    https://github.com/torvalds/linux/blob/master/arch/arm/mach-omap2/control.c

    The "stand alone" should be interpreted as there are no any devices connected to the dm3730 via modem or network.

    The modem subsystem is not part of the dm3730.

    BR

    Tsvetolin Shulev

  • 0 in reply to Cvetolin Shulev-XID
    Intellectual 280 points

    Hi Tsvetolin Shulev,

    Thanks for your helpful answer.

    But, I have some further questions now:

    1. I know a power domain has 5 states named individually on, inactive, cswr, oswr and off; and a clock domain has 2 states named individually active and idle.  But I don't understand What the exact meaning of the term "sleep" is, especially when it's used on a module/subsystem? 

    2.If the UART subsustem remains awake, can the MPU domain, NEON domain and the IVA2 domain be powered off completely?

    3. Since there is an os  on the ARM and DSP, and, even if there is not any application running,  kernels themselves still need cpu clocks, so, can ARM( or DSP) get into retention(or off) state?