tcl/interface/ftdi/xdsv2: fix and clarify EMU* signals

The signal names are changed for consistency with TI's docs and
sources.

Change-Id: Ic5c5314daa20f6f610be8a848399f951d47aa137
Signed-off-by: Matthijs van Duin <matthijs@rinnic-vaude.nl>
Reviewed-on: http://openocd.zylin.com/2231
Tested-by: jenkins
Reviewed-by: Paul Fertser <fercerpav@gmail.com>

diff --git a/tcl/interface/ftdi/xds100v2.cfg b/tcl/interface/ftdi/xds100v2.cfg
index 44508aece1a7c1080e119bd4ddae172dad728214..2628aa0869599587a39ed343a6f66aaefaa1e718 100644 (file)
--- a/tcl/interface/ftdi/xds100v2.cfg
+++ b/tcl/interface/ftdi/xds100v2.cfg
@@ -3,17 +3,56 @@
 #
 # http://processors.wiki.ti.com/index.php/XDS100#XDS100v2_Features
 #
+# Detailed documentation is available only as CPLD verilog source code
+# to the registered TI users.
+#
 
 interface ftdi
 ftdi_vid_pid 0x0403 0xa6d0 0x0403 0x6010
 
 ftdi_layout_init 0x0038 0x597b
+
+#  8000 z - unused
+#  4000 0 > CPLD loopback          (all target side pins high-Z)
+#  2000 z < !( cable connected )   (open drain on CPLD side for $reasons)
+#  1000 0 > EMU1_oe
+#
+#   800 0 > PWR_RST = clear power-loss flag on rising edge
+#   400 z < !( power-loss flag )
+#   200 z < nSRST
+#   100 0 > nSRST_oe
+#
+#    80 z < RTCK
+#    40 0 > EMU0_oe
+#    20 1 > EMU_EN
+#    10 1 > nTRST
+#
+#     8 1 > TMS
+#     4 z < TDO
+#     2 0 > TDI
+#     1 0 > TCK
+#
+# As long as the power-loss flag is set, all target-side pins are
+# high-Z except the EMU-pins for which the opposite holds unless
+# EMU_EN is high.
+#
+# To use wait-in-reset, drive EMU0 low at power-on reset. If the
+# target normally reuses EMU0 for other purposes, clear EMU_EN to
+# keep the EMU pins high-Z until the target is power-cycled.
+#
+# The LED only turns off at USB suspend, which is also the only way to
+# set the power-loss flag manually. (Can be done in software e.g. by
+# changing the USB configuration to zero.)
+#
+
 ftdi_layout_signal nTRST -data 0x0010
 ftdi_layout_signal nSRST -oe 0x0100
-ftdi_layout_signal nEMU_EN -data 0x0020
-ftdi_layout_signal nEMU0 -data 0x0040
-ftdi_layout_signal nEMU1 -data 0x1000
+ftdi_layout_signal EMU_EN -data 0x0020
+ftdi_layout_signal EMU0 -oe 0x0040
+ftdi_layout_signal EMU1 -oe 0x1000
 ftdi_layout_signal PWR_RST -data 0x0800
 ftdi_layout_signal LOOPBACK -data 0x4000
 
 echo "\nInfo : to use this adapter you MUST add ``init; ftdi_set_signal PWR_RST 1; jtag arp_init'' to the end of your config file!\n"
+# note: rising edge on PWR_RST is also needed after power-cycling the
+# target