9 bit serial

Hi, i read the documentation of the atmega328 for 9bit serial, but cant find any hint which bit is send first. Is it the one in the TXB8 or are the other 8 bits send first?

greetings Tarcontar

The diagrams show transmission with the lowest bit (0) first. But why bother with transmission direction, simply follow the sample code for sending and receiving 9 data bits.

since i want to connect to the MDB bus, so i need to know which bit is send first,

the spec is: 1 start, 8 data, 1 mode, 1 end

Then mode should be sent as the 9th bit (TXB8).

ok thx