Thineshan Kathirchelvan (TA)'s Blog (2)

Altium and Eagle are great softwares for PCB design. The softwares can be used to generate schematics and this information (all the parts and connections) can be automatically transferred to a PCB design layout where the parts can be manually arranged and then automatically routed (for relatively simple layouts). Altium also has a simulator and a 3D design layout mode that is helpful for complicated design. Eagle does not have these functions. However it is much less expensive than Altium.…

Transactions: A USB transaction has three parts: the token packet, the optional data packet, and the status packet, which represent the header, payload, and data

acknowledge, respectively. Since USB is host-driven, the host initiates

transactions by sending the token packet. It also sends packets to indicate the

start of each frame, every millisecond. Packets on this layer are taken care

of, so the…