PIC16F18446 - 12 bits ADC gives 16 bits results!!!!

[flotulopex]

Still going ahead with the PIC16F18446...

I'm testing the 12 bits ADC.

First, I had to find out the correspondance between Pin and Channel (I'm using a 20-pin device). Here it is:



The code I use is here:

' PIC 16F18446
' ====== FUSES =====================================================================================
#CONFIG
    __config _CONFIG1, _FEXTOSC_OFF & _RSTOSC_HFINT1 & _CLKOUTEN_OFF & _CSWEN_ON & _FCMEN_ON
    __config _CONFIG2, _MCLRE_ON & _PWRTS_PWRT_64 & _LPBOREN_OFF & _BOREN_SBOREN & _BORV_LO & _ZCDDIS_OFF & _PPS1WAY_OFF & _STVREN_ON
    __config _CONFIG3, _WDTCPS_WDTCPS_31 & _WDTE_SWDTEN & _WDTCWS_WDTCWS_7 & _WDTCCS_LFINTOSC
    __config _CONFIG4, _BBSIZE_BB512 & _BBEN_OFF & _SAFEN_OFF & _WRTAPP_OFF & _WRTB_OFF & _WRTC_OFF & _WRTD_OFF & _WRTSAF_OFF & _LVP_OFF
    __config _CONFIG5, _CP_OFF
#ENDCONFIG

' ====== REGISTERS =================================================================================
' Oscillator Control Register1
OSCCON1 = %01100000 ' $60

' HFFRQ - Oscillator's Frequency Selection Register
OSCFRQ  = %00000010 ' 4MHz

' ====== DEFINES ===================================================================================
DEFINE ADC_BITS 12   'Number of bits in ADCIN result

' ====== VARIABLES =================================================================================
ADC_Value   var word
Serial_Out  VAR PORTB.7
Mode        Var BYTE

' ====== INITIALIZE VARIABLES ======================================================================
Mode        = 84 ' serial com BdRate settings

' ====== TEST PROGRAM ==============================================================================
TEST:
    ADCIN 23, ADC_Value ' ADC channel 23 is RC7
    Serout2 Serial_Out,Mode,["ADC in: ", dEC ADC_Value,13,10]
    PAUSE 500
    GOTO TEST
END

Now, the strange thing is: where I expect a 12 bits result (0..4095), I get a 16 bits value 0..65520 as result and it's amazingly steady, not a digit variation!!!

I'm using a 10 turns 10kOhms pot and that's all.

How can that be please?