Develop a Gumnut subroutine to perform an analog-todigital conversion using successive approximation, returning an 8-bit result in register r1. The Gumnut is connected to an output data register, an input status register, an 8-bit DAC and a comparator as shown in Figure 8.42. The output data register is written at port address 8. The input status register is read at port address 8, and provides the value of the comparator output in the least significant bit, with other bits hardwired to 0.
