FCDEV3B firmware, MCSI and JTAG updates

Mychaela Falconia mychaela.falconia at gmail.com
Mon Apr 15 20:33:24 UTC 2019

Hello FC community,

I got a new release of FCDEV3B official firmware and User's Manual.
Here is the firmware in both prod and nosleep versions:


The differences from the previous 20190128 release are:

* New AT at VSEL command and automatic switching logic for digital voice
via MCSI;

* Fixes in the new TCS3 version of the ACI "high level audio" driver
made in conjunction with the above new feature, fixes which affect the
standard analog audio path as well;

* The low_agc change fixing a bug that was originally made by TI and
went unnoticed all these years, as discussed here before.

And here is the new revision of the User's Manual:


The main updates are in Appendix B for MCSI and Appendix C for JTAG.

Speaking of JTAG, my next project in the order of priority is my long-
desired FreeCalypso UART+JTAG Adapter (FC-UJA), and if you read the
updated FCDEV3B User's Manual, you will hopefully understand why it is
so badly needed.  Connecting an unbuffered FT2232x adapter to Calypso
JTAG pins is NOT safe as explained in the manual update (because of
FTDI's idiotic design of always powering up in UART mode and staying
there until and unless commanded otherwise by a userspace program that
may never run), Openmoko's debug board is not any better because it is
also unbuffered (really, OM, you could have done a better job), the
most-popular-today Flyswatter2 is a product which I cannot endorse
because Tin Can Tools won't publish the schematics for it (and I feel
that using a JTAG adapter without schematics is NOT safe), thus the
only already-existing workable option I could find is the original
Flyswatter, predecessor to the current Flyswatter2 - it is now
discontinued and thus difficult to find, but unlike FS2, TCT did
publish the schematics for the original Flyswatter:


(Yes, the site appears to be in Thailand of all places.  Definitely a
country I plan on visiting soon-ish, but I probably won't be in any
shape to play with JTAG while I am there, as I will be recovering from
pretty major surgery. :)

I found another original Flyswatter unit on ebay (here in USA, not in
Thailand) and it is now on its way to me.  When it arrives, I am going
to play with it, and hopefully come up with some sort of reference
instructions for playing with Calypso JTAG on the FCDEV3B via OpenOCD,
using this old Flyswatter as the only currently-existing adapter that
satisfies all of my criteria.  Then later we are going to transition
to our own FC-UJA.

Another reason why we need to build our FC-UJA (besides providing a
proper JTAG adapter for the FCDEV3B that is not dependent on surplus
Flyswatter stock in Thailand) is that this FC-UJA is a prerequisite
for my desired FreeCalypso handset board.  My FC-UJA will feature not
only a 14-pin JTAG header for connecting to FCDEV3B and similar boards,
but also a special FFC interface carrying JTAG, nTESTRESET and the
UART from FT2232D Channel B, and this special FFC interface will be
required for doing initial bring-up, factory production procedures (fw
loading and RF calibration) and deep development on our handset boards.

Hasta la Victoria, Siempre,
Mychaela aka The Mother

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