Assuming e.g that one part of design transmits 8 bit data word at a time but receiver needs a 16 bit word, we would need to concatenate two 8 bit words together to create a 16 bit word. If both blocks work at same frequency, the receiver shall receive input word every other cycle.
In opposite case e.g where transmitter sends 16 bit word every cycle, the 8 bit receiver shall have to work at twice the frequency to be able to keep up with it. Or maybe data does not come every cycle.
Is there a term used to describe this conversion between data widths?
The first case is simpler, just concatenation. The second is more tricky to implement There maybe need to use some FIFO between the two as well.