7. you need to set up a serial network, which will have one master and four slaves. either spi or i2c can be used. every second, data has to be distributed, such that one byte is sent to slave 1, four to slave 2, three to slave 3, and four to slave 4. if the complete data transfer must take not more than 200 us, estimate the minimum clock frequency which is allowable for spi and i2c. assume there are no other timing overheads.