TMS320F28069: ADC Bandgap Initialization

Figure 8-1 of the TMS320x2806x Technical Reference Manual Literature Number: SPRUH18FJanuary 2011–Revised March 2016 shows an Internal Bandgap with a multiplexer ADCCTL1.ADCREFSEL to select between internal and external references. I am using an external reference in this application - so initialized the ADC with the following code

EALLOW;                                    \
AdcRegs.ADCCTL1.bit.RESET = 1;    /* Master Reset ADC */            \
asm(" RPT#10000 || NOP");                        \
AdcRegs.ADCCTL1.bit.ADCREFSEL = 1; /* Use external reference */        \
AdcRegs.ADCCTL1.bit.ADCBGPWD  = 0; /* Powerdown ADC BG */        \
AdcRegs.ADCCTL1.bit.ADCREFPWD = 1; /* Power reference */        \
AdcRegs.ADCCTL1.bit.ADCPWDN   = 1; /* Power ADC */            \
AdcRegs.ADCCTL1.bit.ADCENABLE = 1; /* Enable ADC */            \
AdcRegs.ADCCTL2.bit.ADCNONOVERLAP = 1; /* Enable non-overlap mode*/     \
AdcRegs.ADCCTL2.bit.CLKDIV2EN = 1; /* ADCClock to be 50% Sysclock */    \
AdcRegs.INTSEL1N2.bit.INT1SEL = 0; /* Connect ADCINT1 to EOC0 */     \
AdcRegs.INTSEL1N2.bit.INT1E  =  1;     /* Enable ADCINT1 */         \
EDIS;

I Powered down the internal bandgap - save a milliwatt - what am I using it for - but ADC outputs all zeroes (yes other code following etc).    

Change one line -

AdcRegs.ADCCTL1.bit.ADCBGPWD  = 1; /* Power up Bandgap */        \

runs fine. Q - are there connections from the internal bandgap not shown in the block diagram? Just want to be sure I am running off the external ref. Also are their any diagrams which show what the bagap power and reference power actually connect to?