+@cindex @code{march} command-line option, Nios II
+@item -march=@var{architecture}
+This option specifies the target architecture. The assembler issues
+an error message if an attempt is made to assemble an instruction which
+will not execute on the target architecture. The following architecture
+names are recognized:
+@code{r1},
+@code{r2}.
+The default is @code{r1}.
+