nios ii version 5.1 service pack 1 has been released and is now available for download. This service pack includes several software fixes that were not included in the 5.1 release. For more information on what is included in this service pack see the Release Notes, linked below. To go straight to the download page, choose Download Service Pack.
read release notes (http://www.altera.com/literature/rn/rn_nios2devkit_51sp1.pdf) download service pack (https://www.altera.com/support/software/download/service_packs/nios/dnl-nios2_51sp1.jsp?wt.mc_id=ni_pw_ni_xx_tx_2_051) --Alan
