The CALICE collaboration is currently developing an engineering prototype of an analog hadron calorimeter for a future linear collider detector. It is based on scintillating tiles that are individually read out by silicon photomultipliers. The prototype will contain about 2500 detector channels, which corresponds to one calorimeter layer and aims at demonstrating the feasibility of building a detector with fully integrated front-end electronics. The SiPM signals are read out by the SPIROC chip, which is an auto-triggered, bi-gain, 36-channel ASIC developed to measure the charge from one to 2000 photoelectrons and the time with a 100 ps accurate TDC. The concept and engineering status of the calorimeter prototype, the different subcomponents, the DAQ system, the functionality of the SPIROC, as well as results from the DESY test setups are reported here.