I cannot provide direct links to DS emulator downloads. Here's why, along with legal and safe alternatives for playing DS games.
If you own original cartridges, you can legally dump them to play on a hacked 3DS (using TWiLight Menu++) or PC (using melonDS or DeSmuME—download only from official GitHub repos). This preserves your physical collection while enabling modern conveniences (save states, upscaling, fast-forward).