# HG changeset patch
# User Mychaela Falconia <falcon@freecalypso.org>
# Date 1553763387 0
# Node ID f57f29dcc6d68b35cee43ab8f9be0750600eeae2
# Parent  17003ecbb9fcfa21b031970f89a8dbf962cc4e13
FCDEV3B-repackaging: updates for working MCSI and flash autodetect

diff -r 17003ecbb9fc -r f57f29dcc6d6 FCDEV3B-repackaging
--- a/FCDEV3B-repackaging	Thu Mar 28 08:04:00 2019 +0000
+++ b/FCDEV3B-repackaging	Thu Mar 28 08:56:27 2019 +0000
@@ -1,6 +1,9 @@
 Repackaging FreeCalypso modem into different physical form factors
 ==================================================================
 
+[This document was originally written in 2018-10; subsequent updates
+ are noted inline in the same bracketed form as this note.]
+
 As of this writing, our FreeCalypso Triband Modem Solution has reached the
 status of a finished product: it is no longer experimental or developmental,
 it is now fully fit for operational use on live public GSM networks in end user
@@ -65,6 +68,10 @@
   introduce a configuration management burden which we are not willing to
   take on.
 
+[2019-03 update: we now have working flash chip type autodetection, and
+ commercial modem products can use a smaller flash+RAM chip, specifically
+ Samsung K5A3240CTM or K5A3281CTM as used by Openmoko.]
+
 * Calypso's unused DSR_MODEM/LPG pin was left unconnected in Openmoko's version
   but on our FCDEV3B it is tied to GND on the board.  Other boards seeking to
   be FreeCalypso-compatible need to have this pin tied to GND as well because
@@ -141,6 +148,10 @@
 * A logic voltage level translating buffer to provide a reset to the flash chip
   that meets its timing requirements;
 
+[2019-03 update: the above is no longer required, you can now use one of the
+ smaller flash chips which are compatible with TI's silly FDP scheme and thus
+ don't need the extra translating buffer IC for reset.]
+
 * 3 pull-down resistors on GPIO3, MCSI_CLK and MCSI_FSYNCH;
 
 * Direct connections to GND on DSR_MODEM and MCSI_RXD pins.
@@ -169,6 +180,9 @@
 situation, the alternative way of tapping into VSP needs to be given
 consideration.
 
+[2019-03 update: we got MCSI working now, please read the Calypso-digital-voice
+ article for more info about both MCSI and VSP options.]
+
 Tapping into VSP is absolutely not possible on our current FCDEV3B, as the
 signals in question are currently routed directly from one BGA to another and
 do not come up to the surface at any accessible point.  The same situation holds