Digital Exchange And Voip

DIGITAL PART There is no way to test MT8981 individually. In order to test it we should have working synchronization block, a working codec and a switch. That was our biggest difficulty. It was impossible to add break points in the hardware. There were only two options either all testing hardware will work or nothing will work. After 6 months of struggle in FYP1 we were able to achieve synchronization between codec and switch. · In first step we try to make circuit on bread board but nothing works · Our codec starts working on Vero board but there was massive noise on the out put · On PCB every thing starts working i.e. codec, switch and synchronization, controller The most time consuming problem on PCB occur when everything was in exact orientation but nothing was working and after 1 month of debugging we found that one solder has weak connection and was resulting massive noise in the output. Our first synchronization circuitry is shown in the figure.