What was found
AT FLIGHT LEVEL AT FL270, STALL FAIL CAUTION POSTED. A SHORT TIME LATER A WARBLER TONE WAS HEARD. CA'S PFD SHOWED LOW SPEED RED RISING UP TO CURRENT SPEED OF 300. STICK SHAKER ACTIVATED AND STOPPED. ANOTHER ACTIVATION OF THE SHAKER HAPPENED AGAIN A MINUTE LATER. WE DISCONNECTED THE AUTO PILOT AND TRANSFERED CONTROL TO FO SIDE AND DECLARED EMERGENCY. PRIOR TO STICK SHAKER ACTIVATION WE COMPLIED WITH AOM1 STALL FAIL CAUTION. R AND L FADEC FAULT 2 ALSO POSTED DURING THE EVENT. TROUBLESHOT IAW FIM 27-35-05-810-805 LAOA/RESOLVER 1 AND 2 MDC MESS. FOUND STALL PROTECTION COMPUTER INOPERATIVE. REMOVED AND REPLACED THE STALL PROTECTION COMPUTER IAW AMM 27-35-01. OPS CHECKED GOOD. NO FADEC MESSAGES NOTED