If it doesn't look like homework it certainly smells like it, as there is absolutely no need practical need (as far as I can tell, but I've been wrong before..) to first store the value of port-pins in R1/bank1 and only afterwards multiply this by a fixed value stored in R0

Looks like exercise with bank switching of registers combined with reading and writing to I/O ports..

Actually, the assignment can almost literally be translated in assembler. There is very little room for creativity...;-) and hence an easy task for the teacher that has to verify/correct the assignment.

rgds
Patrick