bit 1: motor 1, level
bit 2: motor 2, level
bit 3: motor 3, level
bit 4: motor 4, level
bit 5: motor 5, level
bit 6: motor 6, level
bit 7: step, edge
bit 8 set direction, edge

set motor 1 to reverse, others to forward.
10000000
10000001
10000000

step motor 1 and 2 in the set direction:
11000000
11000010
11000000

now reverse motor 2 as well:
11000000
11000001
11000000