RTC on PIC24H

[jpc]

i am trying to get the RTC working on a PIC24HJ128gp202, for some reason i do not get this clock ticking.
I have a 32.768 kHz resonator connected between the SOSCI and SOSCO pins and initialise as follows

Code: Select all

  nvmkey := $55;          
  nvmkey := $AA;
  rtcwren_bit := 1;              //  enable writing to  rcfgcal
  rcfgcal := %1010000000000000;  // enable the RTC
  rtcval := 0;                   // set seconds/minutes to zero
  lposcen_bit := 1;              // enable the LP-oscillator

i must miss something as the clock does not start ticking. If i do not clear rtcval i can see random values on powering up.
I already played with initializing the concerned TRIS bits but no luck so far. for what it is worth i do not see any activity with a scope on the oscillator.
I am running this PIC from the internal osc with PLL, for that reason disabled the primary oscillator in the project-config.
Did anyone here get this working? I am aware of rather dramatic issue's with this RTC in the errata but still could use it to some level.