# ConnectCore9P 9215 Battery backed RTC NVRAM **URL:** \ **Category:** NET+OS\ **Tags:** rtc\ **Created:** [October 13, 2010, 10:20am UTC](https://forums.digi.com/t/connectcore9p-9215-battery-backed-rtc-nvram/4932 "2010-10-13T10:20:59Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![rdeabill](https://avatars.discourse-cdn.com/v4/letter/r/91b2a8/32.png) [@rdeabill](https://forums.digi.com/u/rdeabill)\ **Post date:** [October 13, 2010, 10:20am UTC](https://forums.digi.com/t/connectcore9p-9215-battery-backed-rtc-nvram/4932/1 "2010-10-13T10:20:59Z")
Hi, THe RTC module in the NS9215 supports 64 bytes of NVRAM that is supported by the backup battery according to the datasheet. Has anyone managed to get this working? I have tried accessing it directly, and it seems that I can read and write to it, I can then read back the updated value, but when I hit the reset button it appears that the contents get set back to zero. Any assistance would be very helpfull ---
**Author:** ![bobthomas13](https://avatars.discourse-cdn.com/v4/letter/b/958977/32.png) [@bobthomas13](https://forums.digi.com/u/bobthomas13)\ **Post date:** [October 13, 2010, 11:54am UTC](https://forums.digi.com/t/connectcore9p-9215-battery-backed-rtc-nvram/4932/2 "2010-10-13T11:54:02Z")
Hi, Yes i did… and it is working fine… this piece of code is enough : #include ``` rtc_time.date = 26; rtc_time.dayOfWeek = NA_RTC_THURSDAY; rtc_time.hours = 11; rtc_time.hundredths_second = 0; rtc_time.minutes = 58; rtc_time.month = NA_RTC_AUGUST; rtc_time.seconds = 0; rtc_time.year = 2010; if( naRtcSetTime(device_id,&rtc_time) != NASTATUS_SUCCESS) { perror("RTC Set Time Failed ``` "); exit(1); } try this 🙂 ---
**Author:** ![rdeabill](https://avatars.discourse-cdn.com/v4/letter/r/91b2a8/32.png) [@rdeabill](https://forums.digi.com/u/rdeabill)\ **Post date:** [October 13, 2010, 12:32pm UTC](https://forums.digi.com/t/connectcore9p-9215-battery-backed-rtc-nvram/4932/3 "2010-10-13T12:32:10Z")
Hi, Thanks for the response. I also have the RTC itself working and it keeps time OK onthe backup battery. It appears that there is also some uncommitted NVRAM within the same module, and that is what I am trying to use. According to the NS9215 data sheet P272 it is RTC register address map 0x9006\_0000 – 0x9006\_00BF RTC CSR Space 0x9006\_0000 – 0x9006\_00FC 64-byte Battery Backed RAM Having written this I think I can see the mistake. The datasheet is has both the CSR space and the RAM overlapping. I will give it another try at 0x9006\_00C0 and see if that works better. ---
**Author:** ![bobthomas13](https://avatars.discourse-cdn.com/v4/letter/b/958977/32.png) [@bobthomas13](https://forums.digi.com/u/bobthomas13)\ **Post date:** [October 13, 2010, 1:11pm UTC](https://forums.digi.com/t/connectcore9p-9215-battery-backed-rtc-nvram/4932/4 "2010-10-13T13:11:16Z")
Hi, Check P460 Register address map || Register Address Description 9006 0000 RTC General Control register 9006 0004 12/24 Hour register 9006 0008 Time register 90060 000C Calendar register 9006 0010 Time Alarm register 9006 0014 Calendar Alarm register 9006 0018 Alarm Enable register 9006 001C Event Flags register 9006 0020 Interrupt Enable register 9006 0024 Interrupt Disable register 9006 0028 Interrupt Status register 9006 002C General Status register These are the CSRs… I think you can use the rest of the space 🙂 🙂 ---
**Author:** ![autostudio01](https://avatars.discourse-cdn.com/v4/letter/a/b5e925/32.png) [@autostudio01](https://forums.digi.com/u/autostudio01)\ **Post date:** [October 15, 2010, 4:19am UTC](https://forums.digi.com/t/connectcore9p-9215-battery-backed-rtc-nvram/4932/5 "2010-10-15T04:19:02Z")
Thanks for these info 🙂 ---
**Author:** ![gavello](https://avatars.discourse-cdn.com/v4/letter/g/ccd318/32.png) [@gavello](https://forums.digi.com/u/gavello)\ **Post date:** [October 1, 2013, 9:12am UTC](https://forums.digi.com/t/connectcore9p-9215-battery-backed-rtc-nvram/4932/6 "2013-10-01T09:12:55Z")
what do you use as device\_id? ---
**Author:** ![tuxembb](https://avatars.discourse-cdn.com/v4/letter/t/b38774/32.png) [@tuxembb](https://forums.digi.com/u/tuxembb)\ **Post date:** [October 3, 2013, 12:14am UTC](https://forums.digi.com/t/connectcore9p-9215-battery-backed-rtc-nvram/4932/7 "2013-10-03T00:14:02Z")
Its the identifier of RTC. Take a look at Digi ESP for NET+OS User Guide \> Reference \> NET+OS 7.5 API Reference \> Hardware/Board Support \> Device Drivers \> Real Time Clock Driver (RTC)