tcl/fpga: Support for Xilinx Spartan3 series devices

Tap definition for Xilinx Spartan 3/3E/3A/3AN/3A-DSP devices.

Signed-off-by: George Voicu <razvanvg@hotmail.com>
Change-Id: Ieda2b61fc270840f9192976697fcac259c45e3b8
Reviewed-on: https://review.openocd.org/c/openocd/+/7335
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Tested-by: jenkins

tcl/fpga/xilinx-xc3s.cfg

@@ -0,0 +1,43 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Xilinx Spartan3 generation
+# https://www.xilinx.com/support/documentation/user_guides/ug331.pdf
+
+if { [info exists CHIPNAME] } {
+	set _CHIPNAME $CHIPNAME
+} else {
+	set _CHIPNAME xc3s
+}
+
+# Table 12-4 in https://www.xilinx.com/support/documentation/user_guides/ug332.pdf
+# the 4 top bits (28:31) are the die stepping, ignore them.
+jtag newtap $_CHIPNAME tap -irlen 6 -ignore-version \
+	-expected-id 0x02210093 \
+	-expected-id 0x02218093 \
+	-expected-id 0x02220093 \
+	-expected-id 0x02228093 \
+	-expected-id 0x02230093 \
+	-expected-id 0x02610093 \
+	-expected-id 0x02618093 \
+	-expected-id 0x02620093 \
+	-expected-id 0x02628093 \
+	-expected-id 0x02630093 \
+	-expected-id 0x03840093 \
+	-expected-id 0x0384E093 \
+	-expected-id 0x01C10093 \
+	-expected-id 0x01C1A093 \
+	-expected-id 0x01C22093 \
+	-expected-id 0x01C2E093 \
+	-expected-id 0x01C3A093 \
+	-expected-id 0x0140C093 \
+	-expected-id 0x01414093 \
+	-expected-id 0x0141C093 \
+	-expected-id 0x01428093 \
+	-expected-id 0x01434093 \
+	-expected-id 0x01440093 \
+	-expected-id 0x01448093 \
+	-expected-id 0x01450093
+
+pld create $_CHIPNAME.pld virtex2 -chain-position $_CHIPNAME.tap
+
+source [find fpga/xilinx-dna.cfg]