(no commit message)

diff --git a/docs/pinmux.mdwn b/docs/pinmux.mdwn
index eabac69f4d11317972be9f53b79d8594094894b8..4e33ec0f2a4f92d88e5fdff920126f4ce6a34016 100644 (file)
--- a/docs/pinmux.mdwn
+++ b/docs/pinmux.mdwn
@@ -524,7 +524,12 @@ and for writing, slightly different style:
             if sel[i]:
                 GPIO[GPIO_num].eq(write_byte)
 
-As explained in this video
+As explained in this video <https://m.youtube.com/watch?v=Pf6gmDQnw_4>
+if each GPIO is mapped to one single byte, and it is assumed that
+the `sel` lines are enough to **always** give byte-level read/write
+then the GPIO number *becomes* the Memory-mapped byte number, hence
+the use of `len(sel)` above.  `len(dat_r)//8` would do as well
+because these should be equal.
 
 ## Combining JTAG BS Chain and Pinmux (In Progress)
 [[!img io_mux_bank_planning.JPG size="600x"]]