It looks like confidential information!!
Not really, you're just not looking in the right place. I'd recommend reviewing the training materials used for initial type training for system description.
Though I can't provide you with any specific information regarding the Honeywell Primus 1000 avionics suite and features as installed on the EMB-134/145, the basic design and theory of operation of the system is common to all installations.
I'm looking for the unit that generate the speed tape
The display processors generate the airspeed data symbology (speed tape) displayed on the PFDs. ADC inputs are processed by each display processor and integrated with the appropriate symbology then sent via digital data bus to the PFD. Cross side data sourcing may be selected in case of certain component malfunctions.
Once you look at the system diagram and read the system description, the system architecture becomes pretty easy to visualize.
Best regards,
westhawk