tcl: Support for reading "Device DNA" from Spartan 6 devices.

Most Xilinx FPGA devices contain an embedded, unique device identifier
called the "Device DNA". The identifier is nonvolatile, permanently
programmed into the FPGA, and is unchangeable providing a great serial
/ tracking number.

Debugging was done in https://github.com/timvideos/HDMI2USB/issues/36

Change-Id: Iad03eafb40887f0321a4dc22858a7c3bf37a12b3
Signed-off-by: Tim 'mithro' Ansell <mithro@mithis.com>
Reviewed-on: http://openocd.zylin.com/2960
Tested-by: jenkins
Reviewed-by: Paul Fertser <fercerpav@gmail.com>

diff --git a/tcl/cpld/xilinx-xc6s.cfg b/tcl/cpld/xilinx-xc6s.cfg
index b705ea1fd1c606a4cad4064441ce53653630bd42..9ce7ad4918d43924bc0aa6316faf8bd53ab221cc 100644 (file)
--- a/tcl/cpld/xilinx-xc6s.cfg
+++ b/tcl/cpld/xilinx-xc6s.cfg
@@ -52,3 +52,39 @@ proc xc6s_program_iprog {tap} {
        irscan $tap $XC6S_BYPASS
        runtest 1
 }
+
+set XC6S_ISC_ENABLE 0x10
+set XC6S_ISC_DISABLE 0x16
+set XC6S_ISC_DNA 0x30
+
+# Get the "Device DNA" from the Spartan 6.
+# Most Xilinx FPGA devices contain an embedded, unique device identifier called
+# the "Device DNA". The identifier is nonvolatile, permanently programmed into
+# the FPGA, and is unchangeable providing a great serial / tracking number.
+proc xc6s_get_dna {tap} {
+       global XC6S_ISC_ENABLE XC6S_ISC_DISABLE XC6S_ISC_DNA
+       irscan $tap $XC6S_ISC_ENABLE
+       runtest 64
+       irscan $tap $XC6S_ISC_DNA
+       # Device DNA is 57 bits long, but we can only read 32bits at a time
+       # with OpenOCD.
+       set dna [drscan $tap 16 0 16 0 16 0 9 0]
+       runtest 64
+       irscan $tap $XC6S_ISC_DISABLE
+       runtest 64
+
+       # Convert the binary data into the order impact uses
+       scan $dna "%x %x %x %x" v1 v2 v3 v4
+       set bin_dna [string reverse [concat [format "%09b" $v4][format "%016b" $v3][format "%016b" $v2][format "%016b" $v1]]]
+
+       # Return a hex version of binary
+       scan [format "0b%s" $bin_dna] "%i" hex_dna
+       return $hex_dna
+}
+
+# Print out the "Device DNA" in the same format that impact uses.
+proc xc6s_print_dna {tap} {
+       set hex_dna [xc6s_get_dna $tap]
+
+       puts [format "DNA = %57b (0x%x)\n" $hex_dna $hex_dna]
+}