C2000: Why is EALLOW required before call to ADC Calibration?

Other Parts Discussed in Thread: TMS320F28335

Hello,

According to the TMS320F28335 datasheet (page 49), the system control registers are not EALLOW protected, so why does the compiler manual (page 29) specify the ADC calibration function call as shown below.

Stephen

EALLOW;
SysCtrlRegs.PCLKCR0.bit.ADCENCLK=1;
(*ADC_Cal) ();
SysCTRLRegs.PCLKCR0.bit.ADCENCLK=0;
EDIS;