+                                       /** Re-enables the AVR's JTAG bus in software, until a system reset. This will re-enable JTAG debugging
+                                        *  interface after is has been disabled in software via \ref JTAG_DISABLE().
+                                        *
+                                        *  \note This macro is not available for all architectures.
+                                        */
+                                       #define JTAG_ENABLE()               do {                                     \
+                                                                               __asm__ __volatile__ (               \
+                                                                               "in __tmp_reg__,__SREG__" "\n\t"     \
+                                                                               "cli" "\n\t"                         \
+                                                                               "out %1, %0" "\n\t"                  \
+                                                                               "out __SREG__, __tmp_reg__" "\n\t"   \
+                                                                               "out %1, %0" "\n\t"                  \
+                                                                               :                                    \
+                                                                               : "r" (MCUCR & ~(1 << JTD)),         \
+                                                                                 "M" (_SFR_IO_ADDR(MCUCR))          \
+                                                                               : "r0");                             \
+                                                                           } while (0)
+