A319 Captain reported a double Flight Control Unit failure during descent. With only basic flight instruments and standby altimeter available; crew performed a visual approach and landing.

Narrative

While descending through FL230 received an ECAM message FCU (Flight Control Unit) 1 Fault/PFD (Primary Flight Display) BARO REF: STD ONLY. We were unable to set the barometric altimeter to local settings. Within 5 minutes while running ECAM and checklists we received a further ECAM alert of auto pilot off; auto thrust off; and auto flight FCU 1+2 Fault. We leveled at 6000 and began to run checklists for the new ECAM faults. I observed that I was down to the basics of flight instrumentation; with no Flight Director; and only the bird" for flight guidance. The standby altimeter was the closest to reasonable altitude. I had the airport in sight and good visibility. The sun was setting and I was not interested in a night time landing with only basic instrumentation. I [requested priority handling] and requested a visual approach to Runway XX. With airspeed callouts from my FO; I made the visual approach and landed Runway XX without incident. Local emergency equipment followed us to the gate.Cause: Double FCU unit failure resulting in loss of Auto pilot; auto thrust; basic Flight Director and unreliable altimeter setting. [Requested priority handling] and a visual approach conducted to the runway. No suggestions to mitigate risks."