Converting 32 bit JTAG ID to Avr::TargetSignature instance

src/DebugToolDrivers/Protocols/CMSIS-DAP/VendorSpecific/EDBG/AVR/ResponseFrames/AVR8Generic/GetDeviceId.hpp

@@ -31,6 +31,35 @@ namespace Bloom::DebugToolDrivers::Protocols::CmsisDap::Edbg::Avr::ResponseFrame
                      */
                     return TargetSignature(payloadData[3], payloadData[2], payloadData[1]);
                 }
+                case Avr8PhysicalInterface::JTAG: {
+                    /*
+                     * When using the JTAG interface, the get device ID command returns a 32 bit JTAG ID. This takes
+                     * the following form:
+                     *
+                     *  VVVV PPPPPPPPPPPPPPPP MMMMMMMMMMM L
+                     *
+                     *  - (V) - Version nibble (4 bits)
+                     *  - (P) - Part number (this is typically the AVR signature excluding the manufacture
+                     *          byte (0x1E)) (16 bits)
+                     *  - (M) - Manufacture identity (11 bits)
+                     *  - (L) - LSB indicator (1 bit)
+                     *
+                     * We convert this into a Avr::TargetSignature by extracting the relevant part number and assuming
+                     * a manufacture byte of 0x1E.
+                     *
+                     * TODO: We're not considering the value of the LSB indicator bit. We're just assuming it will
+                     *       always be MSB. Is this assumption correct?
+                     */
+                    auto jtagId = static_cast<std::uint32_t>(
+                        (payloadData[0] << 24) | (payloadData[1] << 16) | (payloadData[2] << 8) | (payloadData[3])
+                    );
+
+                    return TargetSignature(
+                        0x1E,
+                        static_cast<unsigned char>((jtagId << 4) >> 24),
+                        static_cast<unsigned char>((jtagId << 12) >> 24)
+                    );
+                }
                 default: {
                     return TargetSignature(payloadData[0], payloadData[1], payloadData[2]);
                 }