changeset 678:edaceb78719a

doc/Leonardo-target: Tango unused Calypso signals update
author Mychaela Falconia <falcon@freecalypso.org>
date Sat, 20 Jun 2020 05:08:39 +0000
parents 91d9f8506420
children 52ee171ff5e4
files doc/Leonardo-target
diffstat 1 files changed, 5 insertions(+), 11 deletions(-) [+]
line wrap: on
line diff
--- a/doc/Leonardo-target	Sat Jun 20 04:32:45 2020 +0000
+++ b/doc/Leonardo-target	Sat Jun 20 05:08:39 2020 +0000
@@ -122,14 +122,8 @@
 existed once beyond our known schematics, we would rather leave a few floating
 inputs than risk causing a driver conflict on some unknown board.
 
-In the case of Tango these 3 just-mentioned Calypso signals are contained inside
-the module (not brought out), and it is currently unknown if they are simply
-unconnected or if perhaps they are tied to either GND or V-IO inside the module.
-The Tango manuf's original fw leaves these signals in their power-up default as
-Calypso inputs, hence we do the same currently in order to not risk causing a
-short.  At some later time when our finances allow doing so, we may send a
-sacrificial Tango module for destructive PCB reverse eng and see what is really
-done with these Calypso signals - if they are really unconnected, then we can
-change the code to switch them to outputs, just like we have done for the
-gtamodem target where the original manuf's official fw also left a bunch of
-floating inputs.
+In the case of Tango these 3 just-mentioned Calypso signals (as well as
+BCLKX/GPIO6) have been confirmed to be unconnected at their Calypso ball pads
+(not brought out externally, not used internally for anything, not tied or
+pulled to either GND or V-IO), thus we configure them as dummy outputs,
+eliminating floating inputs.