During execution of RedBoot configured for a Sparc Leon3 IP core the process hits a trap on instruction fetch in the RedBoot routine _timer_poll(). The debugger history and assembly are attached. The process will execute RedBoot commands at the command prompt and otherwise behave normally until a branch instruction to do_idle and subsequently net_io_test(), that is where execution eventually fails. Oddly the process runs without fault when DEBUG command options are selected during configuration of the build with configtool, trouble begins when the DEBUG options are again removed. The DEBUG instructions appear in the ethernet modules and in RedBoot's net_io. If this is a timing issue can someone please suggest what parameters can be tweeked to resolve the traps, or if a memory alignment problem can someone offer a memory map and alignment parameters? Are there configuration selections in the amba bus header file, those might be helpful too. The compiler is sparc-elf-gcc-3.4.4 I'm using two additional compilation flags -msoft-float and D-ECOS. The system configuration is also attached to this email. Thank you for directions. -Les