A 9S12 with an 8-bit DAC is used to create a software-controlled analog output. The 8-bit signed DAC (using offset binary format) is connected to the 9S12 Port B and has a -5 V to +5 V range as shown in the following table. N is the Port B output (DAC input), and V is the DAC output
a) Derive the linear relationship between N and V. Show both the equation that expresses V in terms of N and the equation that expresses N in terms of V.
b) What is the DAC precision? State the units.
c) What is the DAC resolution? State the units.
d) Write a 9S12 function, DAout, which takes the desired voltage (in millivolts) and outputs the appropriate value to Port B. The 16-bit signed input parameter is passed by reference on the stack. Here are a couple of typical calling sequences:
