6 Replies Latest reply on Aug 10, 2015 7:22 AM by ab-tools

    V_VBAT_BCKP : Questions


      Hello everyone,


      I'm currently developing a board using the Intel Edison compute module and I have used the specified supercap PAS3225P2R6143 from Tayio Yuden (Edison compute module Hardware Guide (jan. 2015) p. 14-37-38 http://download.intel.com/support/edison/sb/edisonmodule_hg_331189004.pdf) to hold the Edison RTC alive.


      Can anyone clarify the use of the pin 23 V_VBAT_BCKP. Is it possible to power the complete compute Edison through this pin for a while? I found in this document two locations which I cannot interpret correctly because it's not clear for me.

      p. 14 (table)

      23          V_VBAT_BKUP     Real-time clock (RTC) backup battery input

      (this one is clear, it's for RTC)

      p. 37

      "The PMIC has a dedicated charging subsystem for a backup battery supply that could be either a rechargeable coin cell batteries or super-capacitors. This backup subsystem allows for interruption of the main supply for a short period of time, such as changing a main system battery."

      (With this sentence, I think that we can maybe power the Edison for a while)


      In this document, at p. 37, there's a little C code to access the PMIC registers for configuration. Where's the sources located in the yocto release (the file drivers/platform/x86/intel_scu_pmic.c). I could not find this one? (I use yocto rel2 ww05-15 distro.) So it could be difficult to communicate with the PMIC

      Thank you in advance for answering and tip!