I want to exercise the SDADC on the MPC5746. I use the following configuration parameters :
SDADC_0.MCR.B.MODE = 1; /* Single ended input */
SDADC_0.MCR.B.VCOMSEL= 0; /* IMP+ = AN; INP- = VREFN */
SDADC_0.MCR.B.HPFEN = 0; /* Disable HP filter */
SDADC_0.CSR.B.BIASEN = 0 /* Disable bias */
SDADC_0.MCR.B.PGAN = 0; /* 000: gain = 1 */
SDADC_0.MCR.B.PDR = 0; /* 0: OSR = 24; output data rate = sampleClk/(2*OSR) */
Since SDADC is 16 bit, and VREF is 5V, to convert from sample value to Voltage i use the equation:
Value-in-mV = (register_value * 5000 )/ 0xFFFF;
When i execute the program, the values I get half of the expected values. I probed the pins but find the actual values are correct, so I do not suspect any hardware issue.
Something in the SDADC configuration appears to be causing this divide by 2.
Appreciate any suggestions.