FPGA and Microcontroller

NIOS is the micro-controller. The DallasSemi device is a One-Wire part. You access the sensor using either software with a PIO or you can build a state-machine implemented in the FPGA using VHDL or Verilog.

To use software, add a one (1) bit Bidirectional PIO device to the NIOS using SOPC. Connect its single output pin to the pin of the sensor. Software controls the output level, if it is driving or tri-state mode, and can read the pin for getting the data from the sensor. The program can be written in C, Assembly, Forth, etc. I've done several different protocols in the last few years. You will need to follow the sensor's protocol closely to get the temperature value from the sensor as well as the other bit fields in the part.