I want to expand some uart ports with sc16is752 based on embeded linux OS. There are 6 sc16is752 chips on iic bus at 100k/s clock rate. When testing, some exception appeared.
a. baud rate 9600
b. 512B per second
c. dual full duplex, loopback， self-transmitting and self-receiving.
Sometimes, maybe only two chips work. other chips could send data, but no recieving. At Last Day, maybe ABC are ok, DEF can not work; And Second Day, maybe DEF are ok.
Sometimes, one chip's interruption pin generate interruption frequently, so that, the linux kernel halted.
So, How many sc16is752 could be used at most on iic bus at the same time? What make the chips unstable?