It was a hybrid processor, 16 on the inside 8 bit on the bus. From Wikipedia. The Motorola 6809 ("sixty-eight-oh-nine") is an 8-bit microprocessor with some 16-bit features. It was designed by Motorola's Terry Ritter and Joel Boney and introduced in 1978. Although source compatible with the earlier Motorola 6800, the 6809 offered significant improvements over it and 8-bit contemporaries like the MOS Technology 6502,…
For those who don't know the history, the 6502 was initially the 6501, created to be a cut-down, cheaper alternative to the 6800 by many of the same engineers who designed the 6800 at Motorola. Since the idea of copyrighting an instruction set wasn't really a thing yet, the 6501 started out very, very similar to the 6800. Their goal was to basically make a clone of the 6800, except to cut costs so dramatically many changes had to be made, features cut, registers, instructions and interrupts removed. Even so, the 6501 was still pin for pin compatible with the 6800 until Motorola sued Mostek over it. The settlement was that Mostek change the pin out, so the 6501 became the 6502.
Chuck Peddle was the head technical sales person for the 6800 at Motorola and in every customer meeting where he showed early prototypes, customers loved the CPU but said the price was simply a non-starter. He got so sick of hearing it, he quit, joined Mostek, recruited some 6800 engineers and started the 6500 chip project to compete.