• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 62 subscribers
  • Views 656 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

Internal Osc on TPS65910 possible?

JOHN CARRARA
Intellectual 485 points
Other Parts Discussed in Thread: OMAPL138, AM3517, AM3505, AM3715, DM3730, TPS65910

Using TPS65910A1RSL for OMAPL138 with boot mode pins on TPS65910A1RSL connected as BOOT0=GND, BOOT1=VRTC (recommended by the"TPS65910 User Guide For OMAPL-137, OMAPL-138, and TMS320C674x Family of Processors")

Can the internal RC oscillator be used or do I have to connect external crystal or oscillator? The datasheet for TPS65910A1RSL indicates the internal oscillator usage is dependent on the BOOT pin configuration.

The document says:

The device supports three embedded power sequences selectable by the device BOOT pins.

BOOT0 BOOT1 Processor Supported

0 0 AM3517, AM3505

1 0 OMAP3 Family, AM3715/03, DM3730/25

0 1 EEPROM sequence

The document also states:

Default selection of a 32-kHz RC oscillator versus 32-kHz crystal oscillator or external square-wave 32- kHz clock depends on the Boot mode or device version (EEPROM programming): •

BOOT1 = 0, BOOT0 = 1: quartz oscillator or external square wave 32-kHz clock default •

BOOT1 = 0, BOOT0 = 0: 32-kHz RC oscillator default

This addresses two (0,1 and 0,0) but does not address the recommended BOOT1=1 and BOOT0=0 (1,0).

What is the behavior when BOOT1=1 and BOOT0=0?

Does Table 4 in TPS65910 User Guide For OMAPL-137, OMAPL-138, and TMS320C674x Family of Processors imply RC OSC is not an option (CK32K_CTRL as 1=RC_OSC)? (I thought I saw somewhere where these were factory set. "The correct power-up sequence is configured in the EEPROM (factory programmable only).")

DEVCTRL_REG RTC_PWDN 0 = RTC in normal power mode                                  1

                                                      1 = Clock gating of RTC register and logic, low-power mode

DEVCTRL_REG CK32K_CTRL 0 = Clock source is crystal/external clock.            Crystal

1 = Clock source is internal RC oscillator

  • 0
    TI__Genius 10885 points

    1) Can the internal RC oscillator be used or do I have to connect external crystal or oscillator?

    A) The internal oscillator can be used if you ground OSC32KIN and let OSC32KOUT float.

    2) What is the behavior when BOOT1=1 and BOOT0=0?

    A) The BOOT1=1, BOOT0,=0 specific settings for the TPS65910A1RSL can be found in the User's Guide here: http://www.ti.com/lit/ug/swcu071a/swcu071a.pdf 

    3) Does Table 4 in TPS65910 User Guide For OMAPL-137, OMAPL-138, and TMS320C674x Family of Processors imply RC OSC is not an option (CK32K_CTRL as 1=RC_OSC)?

    A) No, the internal oscillator is the default clock source and will still be used if an external crystal is not present, this just indicates that the device will accept an external source.