What was found
AT CRUISE FL340, AIR PACK 1 AND 2 FAULT ECAM MESSAGE APPEARED. PROCEDURE TO TURN NR 1 PACK OFF, DID NOT DO THIS SINCE NR 2 PACK WAS INOPERABLE. DECLARED AN EMERGENCY AND EXECUTED RAPID DESCENT MANEUVER. DID NOT LOSE CABIN PRESSURE, LEVELED OFF AT 10,000 FEET. LANDED WITHOUT FURTHER ISSUES. MAINTENANCE REPLACED COMPRESSOR OUTLET TEMPERATURE SENSOR IAW AMM 21-61-11. ACCOMPLISHED SATISFACTORY OPERATIONAL CHECK IAW AMM 21-61-00. AIRCRAFT WAS GROUNDED.