What was found
AT CRUISE FL 370 ABOUT 60 MIN INTO FLIGHT, HAD A MOMENTARY "TIRE FAIL" AND ALL TIRES WERE MISSING FROM DISPLAY, THEN THE INDICATIONS RETURNED TO NORMAL. AT FL 250 DESCENDING TO 10,000, WE GOT THE LEVEL 2 "TIRE FAIL" INDICATION WITH THE CAWS ALERT "TIRE FAILURE". WE RAN THE QRH GUIDANCE, AND WHEN WE EXTENDED THE GEAR, THE INDICATIONS DID NOT RETURN TO NORMAL SO WE DECLARED AN EMERGENCY WITH TOWER. LANDING WAS GOOD. 1.14G, 50 FLAPS, FELT NORMAL ON ROLLOUT. FIRE CHIEF INSPECTED TIRES AND NOTIFIED US EVERTHING WAS NORMAL SO WE BLOCKED IN. REMOVED AND REPLACED THE (TIRE PRESSURE/BRAKE TEMPERATURE COMPUTER) IAW PER AMM 32-46-02. RTS TEST PASS. A/C OK FOR SERVICE.