In a small mixing bowl, whisk together the brown sugar, soy sacuce, vinegar, and juice. 

Place pork chops in a plastic zip top bag. Pour the marinade over the pork. Squeeze as much air as possible out of the bag, then seal the bag. Marinate for at least 4 hours. 

Preheat a grill over medium high heat and lightly oil the grates.

Add the pork chops to the grill, along with the pineapple. Turn the heat to medium low under the pork (pineapple can remain at a higher temperature). Grill until the pork has nice grill marks and is browned, 4-5 minutes. 

Flip the chops and the pineapple and repeat on the other side. Check the temperature of the pork and remove at 140 to a plate. Tent with foil while you prepare the salsa.

For the salsa: Chop the grilled pineapple into small, bite sized pieces (think diced tomatoes). Add to a medium sized mixing bowl. Add the mango, red pepper and cilantro, and drizzle with the lime juice and zest. Stir together. 

Serve the pork  topped with the salsa.