r5611 - trunk/gta02-core/docs/ecn

[daveb at docs.openmoko.org]

Author: daveb
Date: 2009-09-05 23:35:47 +0200 (Sat, 05 Sep 2009)
New Revision: 5611

Added:
   trunk/gta02-core/docs/ecn/ecn0039.txt
Modified:
   trunk/gta02-core/docs/ecn/STATUS
Log:
Rask's SPI 0R ecn - Rask Ingemann Lambertsen <ccc94453 at vip.cybercity.dk>


Modified: trunk/gta02-core/docs/ecn/STATUS
===================================================================
--- trunk/gta02-core/docs/ecn/STATUS	2009-09-05 21:28:52 UTC (rev 5610)
+++ trunk/gta02-core/docs/ecn/STATUS	2009-09-05 21:35:47 UTC (rev 5611)
@@ -38,6 +38,7 @@
 0036    Execute Removal of decoupling capacitor C3020
 0037    Execute Route ROUT1/LOUT1 back to LINE1/LINE2 input
 0038    Discuss Loudspeaker EMI filter
+0039	Discuss	Insert 0R resistors into SPI signals
 
 Open ECNs
 ---------
@@ -61,3 +62,4 @@
 0036    AUDIO
 0037    AUDIO
 0038    AUDIO
+0039	CPU, LCM

Added: trunk/gta02-core/docs/ecn/ecn0039.txt
===================================================================
--- trunk/gta02-core/docs/ecn/ecn0039.txt	                        (rev 0)
+++ trunk/gta02-core/docs/ecn/ecn0039.txt	2009-09-05 21:35:47 UTC (rev 5611)
@@ -0,0 +1,33 @@
+Insert 0R resistors into SPI signals
+
+
+The SC32442B SPI interface running at 13 MHz or faster has timing problems[1]
+that we might need to patch up externally. Following ECN0001 (Glamo removal)
+and ECN0034 the SPI interface exposed at the debug connector will now be routed
+to the alternative SPI1 pins of the LCD interface. There is some uncertainty
+about the SPICLK1 signal there[2]. Finally, the SPI1 pins currently routed to the
+accelerometer have EINT capability while the debug connector ones do not, so to
+make better use of EINT pins, we should find out if the two sets of SPI pins can
+be swapped.
+
+The change is to insert a 0R resistor into all the SPI signals:
+
+SPICLK0/GPE13
+SPIMOSI0/GPE12
+SPIMISO0/GPE11
+EINT11/nSS1/GPG3
+EINT13/SPIMISO1/GPG5
+EINT14/SPIMOSI1/GPG6
+EINT15/SPICLK1/GPG7
+VD9/SPICLK1/GPD1
+VD17/SPIMOSI1/GPD9
+VD16/SPIMISO1/GPD8
+
+Impact: We won't likely have enough 0R resistors supplied by OM and therefore
+need to buy some.
+
+[1] https://lists.openmoko.org/pipermail/openmoko-kernel/2008-September/005261.html
+[2] https://lists.openmoko.org/pipermail/gta03/2009-May/000210.html
+
+
+Author: Rask Ingemann Lambertsen <ccc94453 at vip.cybercity.dk>